How Do Our Eyes Really Work? (The Story of Vision) | Only Human

Summary

The video script explores the critical importance of vision to human life, highlighting the complex process of sight and the various challenges that threaten it. It discusses the global issue of poor vision, the impact of uncorrected refractive errors, and the devastating effects of blindness. The narrative delves into personal stories of individuals overcoming vision loss, the role of technology in vision correction, and the potential of medical advancements like stem cell research and retinal prosthetics. The script also addresses the broader implications of vision loss on society and the economy, emphasizing the need for accessible eye care and the transformative power of restoring sight.

Takeaways

• 👀 Sight is a critical sense, with over 2.5 billion people globally experiencing vision problems due to unaddressed issues.
• 🌟 The eye is a complex organ, processing light through a series of transparent and opaque structures to transmit visual data to the brain.
• 💡 Vision loss can occur due to various factors, including age-related conditions, myopic macular degeneration, and injuries from accidents or war.
• 🌍 Globally, uncorrected refractive errors are the leading cause of visual impairment, affecting productivity and quality of life, and are particularly prevalent in developing countries.
• 👓 Glasses and other vision correction tools have evolved from simple devices to not only correct vision but also integrate technology and fashion.
• 🛠️ Advances in eyewear technology include protective lenses that block harmful blue light from digital devices and ultraviolet rays from the sun.
• 🩺 Medical interventions such as cataract surgery and corneal transplants can restore vision and significantly improve quality of life.
• 🧬 Research into stem cell therapy and gene expression offers hope for regenerating damaged retinal cells and potentially curing diseases like macular degeneration.
• 🌐 Organizations like Orbis and Vision Brigades work to combat blindness by training local eye care professionals in developing countries.
• 🔋 Wearable technology in eyewear is being developed to monitor health metrics and deliver drugs, further blending medical needs with technological innovation.

Q & A

What is the significance of the eyes in terms of human senses?

Sight is arguably our most important sense as it allows us to perceive and interpret the world around us. The eyes, often referred to as the windows to the soul, are delicate orbs that work in conjunction with the brain to create images and help us navigate our environment.

How do photoreceptors contribute to the process of sight?

Photoreceptors, found in the retina, are responsible for sensing light. There are two types: rods, which are sensitive to low levels of light, and cones, which are responsible for color vision and function best in bright light. The information from these photoreceptors is transmitted to the brain, allowing us to see and interpret the visual world.

What is the role of the optic nerve in vision?

The optic nerve transmits coded electrical impulses from the retina to the brain. It gathers neurons at the optic disk and forms a bundle that carries visual information. The optic nerve is crucial for processing and interpreting the images we see.

What is the impact of uncorrected refractive error on global productivity?

Uncorrected refractive error is a leading cause of visual impairment and significantly affects global productivity. It is estimated to cost 272 billion dollars per year, impacting individuals' abilities to learn, work, and enjoy life quality. Correcting this issue is considered a worthwhile investment compared to the benefits it could bring.

How does the brain process visual information?

The brain processes visual information through various regions in the cerebral cortex. These regions communicate actively with each other to build the images we perceive. The brain's ability to make guesses and inferences about what we see is a testament to its power and complexity.

What is the significance of the development of sensory substitution devices like the brain port?

Sensory substitution devices like the brain port offer a way for individuals with visual impairments to experience the visual world. By translating visual information into electrical stimuli that can be perceived through other senses, such as touch or hearing, these devices can help restore a sense of sight and improve quality of life.

What is the role of eyeglasses in vision correction and fashion?

Eyeglasses serve a dual purpose in vision correction and fashion. They correct refractive errors, helping individuals see clearly, and also function as a fashion accessory, allowing people to express their personal style. The convergence of medical necessity and fashion in eyewear has led to a wide variety of designs and the acceptance of glasses as a normal part of everyday life.

How does the World Health Organization prioritize uncorrected refractive error?

The World Health Organization recognizes uncorrected refractive error as the leading cause of visual impairment and the second leading cause of blindness worldwide. This acknowledgment highlights the importance of addressing this issue on a global scale.

What are the challenges associated with treating corneal diseases in developing countries?

Corneal diseases are common in developing countries, where access to eye banks and advanced medical facilities is limited. The high cost of processing donor corneas and cultural beliefs can also hinder corneal transplants. Organizations like ORBIS and collaborative research efforts aim to train local professionals and improve eye care in these regions.

What is the potential impact of stem cell therapy in treating vision-related conditions?

Stem cell therapy holds promise in treating various vision-related conditions, including age-related macular degeneration and corneal damage. By using a patient's own cells, researchers aim to replace damaged photoreceptor cells and restore vision, offering a potential solution for conditions that currently lack effective treatments.

Outlines

00:00

👀 The Marvel of Vision and the Global Vision Crisis

This paragraph delves into the significance of vision and the complex process that allows us to see. It highlights the fact that sight is our most important sense, involving a series of intricate steps from light entering the eye to the brain interpreting visual information. The paragraph also discusses the global quiet vision crisis, affecting billions of people due to various forms of blindness and visual impairments, emphasizing the impact on productivity and quality of life. It introduces the topic of the video, which is the story of sight, the eyes, and the brain's协同作用 to create images of the world, as well as the scientific, medical, and technological advancements致力於 preserving and restoring our vision.

05:01

👁️‍🗨️ Understanding the Eye's Photoreceptors and Visual Processing

This section explains the role of photoreceptors, rods, and cones, in the retina and their different reactions to photons, which initiate the sensation of seeing. It further explores the process of visual information pre-processing in the retina before it's sent to the brain. The paragraph also discusses the complexity of the brain's visual processing, the optic nerve's path, and the brain's ability to infer and make guesses about what it 'sees'. It presents the case of Chris, an Iraq war veteran with traumatic brain injury and vision loss, illustrating the brain's adaptability and the challenges of vision rehabilitation.

10:02

🧠 Brain's Role in Visual Perception and Rehabilitation

This paragraph examines the brain's role in visual perception, emphasizing the cerebral cortex's function in higher-order visual processing. It describes how different brain regions communicate to build the images we see and how the brain uses sensory substitution to perceive the world without direct visual signals. The paragraph introduces innovative technologies like the brain port, which uses sensory substitution to help blind individuals 'see' through other senses. It also addresses the issue of various causes of blindness and the potential for technological solutions to overcome visual impairments.

15:03

👓 The Impact of Uncorrected Refractive Error on Society

This section discusses the widespread issue of uncorrected refractive error, its impact on society, and the economic burden it imposes. It provides statistics on the number of people affected and the associated costs to the medical industry and global productivity. The paragraph also explores the transformative power of correcting refractive errors through glasses, the importance of vision care, and the potential economic benefits of addressing this issue on a global scale.

20:04

👵 Aging and Vision: The Prevalence of Presbyopia and Cataracts

This paragraph focuses on the common age-related vision problems, such as presbyopia and cataracts. It explains the causes and effects of these conditions, including the hardening of the crystalline lens and the clouding of vision. The section also touches on the history and evolution of eyeglasses, their role in fashion and clinical needs, and the emerging trends in eyewear that combine style with health benefits.

25:05

🌞 Blue Light and UV Protection: The Role of Eyewear

This section discusses the dangers of blue light and UV radiation on our eyes and health. It explains how excessive exposure to these types of light can lead to various eye conditions and sleep disorders. The paragraph highlights the solutions provided by eyeglass manufacturers to block blue light and protect the eyes. It also emphasizes the importance of raising awareness about the need for protective eyewear, similar to the use of sunscreen, and the efforts to reduce the impact of these harmful lights on our health.

30:07

🦋 Advances in Vision Correction and the Future of Eye Care

This paragraph outlines the advancements in vision correction, including the development of contact lenses and their various applications. It discusses the potential of contact lenses for biometric measuring, drug delivery, and integration of technologies similar to Google Glass. The section also explores the future possibilities of vision correction, emphasizing the importance of continued research and innovation in eye care to improve and preserve vision for individuals worldwide.

35:10

🛠️ Surgical Interventions and Innovations in Treating Eye Diseases

This section delves into surgical interventions for eye diseases, highlighting cataract surgery as a common and successful procedure. It discusses the efforts to address the backlog of unoperated cataracts in developing countries through initiatives like Vision Brigades. The paragraph also covers the role of organizations like ORBIS in training local eye care professionals and the advancements in treating corneal diseases, including the use of stem cell transplantation. The focus is on the importance of collaborative efforts to prevent blindness and improve eye health globally.

40:12

🌐 The Epidemic of Myopia and Its Consequences

This paragraph addresses the increasing prevalence of myopia, or nearsightedness, especially in Asia, and its associated risks, such as myopic macular degeneration. It discusses the genetic and environmental factors contributing to the rise in myopia and the impact of lifestyle on its development. The section also highlights research findings on the benefits of spending time outdoors to reduce the risk of myopia and the potential strategies to slow its progression. The focus is on the need for awareness and action to mitigate the epidemic and its long-term consequences on vision health.

45:12

💡 Restoring Sight: Innovations and Humanitarian Efforts

This paragraph showcases the cutting-edge research and technological advancements aimed at restoring sight to those with retinal diseases and damage. It highlights the work of Dr. Sheila Nirenberg and her team, who have decoded the retina's signal to the brain and developed a transmitter to generate the code. The section also presents the potential of optogenetics, a light-sensitive protein, in restoring vision. The paragraph emphasizes the importance of continued research and the dedication of individuals and organizations in the mission to combat blindness and improve the quality of life for those affected.

Keywords

💡Vision

Vision refers to the ability to see and interpret visual information. In the context of the video, it is the primary sense discussed, and the focus is on its importance, the complex process it entails, and the various conditions and technologies that can affect or restore it. The video emphasizes the significance of vision to our daily lives and the global efforts to combat vision loss.

💡Photoreceptors

Photoreceptors are specialized cells in the retina that respond to light and convert it into electrical signals. Rods and cones are the two types of photoreceptors, with rods being sensitive to low light levels and cones responsible for color vision and high visual acuity. The video highlights the role of photoreceptors in the vision process and how their dysfunction can lead to various forms of blindness.

💡Retinal Degeneration

Retinal degeneration refers to the deterioration of the retina's ability to function properly, often resulting in vision loss. The video discusses conditions such as age-related macular degeneration (AMD) and retinitis pigmentosa (RP), which are types of retinal degeneration that can lead to significant impairment or blindness. These conditions are often progressive and can be caused by genetic or environmental factors.

💡Cataracts

Cataracts are a clouding of the lens in the eye that can lead to vision loss. They are a common age-related condition and can also be caused by injury or certain health issues. The video emphasizes the impact of cataracts on global blindness and the effectiveness of cataract surgery in restoring vision, often with the use of intraocular lenses to correct refractive errors.

💡Glaucoma

Glaucoma is a group of eye diseases that damage the optic nerve, often due to increased pressure within the eye. It can lead to irreversible vision loss if left untreated. The video discusses the risk factors for glaucoma, such as age and ethnicity, and the importance of regular eye exams for early detection and treatment to prevent blindness.

💡Myopia

Myopia, or nearsightedness, is a common refractive error where close objects appear clearly, but distant objects appear blurry. The video discusses the increasing prevalence of myopia, particularly in Asia, and its association with environmental factors such as reduced time spent outdoors. It also highlights the potential risks of severe myopia, including retinal detachment and myopic macular degeneration.

💡Stem Cell Therapy

Stem cell therapy involves the use of stem cells to treat or prevent diseases or conditions, including those affecting the eye. In the context of the video, it is discussed as a potential treatment for retinal degeneration, where stem cells could replace damaged photoreceptor cells and restore vision. This therapy is still in the research and development phase but holds promise for the future of vision restoration.

💡Visual Cortex

The visual cortex is the area of the brain responsible for processing visual information received from the eyes. It is involved in the interpretation of the electrical signals from the retina into the images we perceive. The video discusses the complexity of the visual cortex and its ability to process and make sense of the vast amount of visual information, as well as its role in conditions like neglect, where a person is unaware of visual input from a certain area of their visual field.

💡Refractive Error

Refractive error is a vision condition where the eye does not focus light properly on the retina, resulting in blurry vision. Common types include myopia (nearsightedness), hyperopia (farsightedness), and astigmatism. The video emphasizes the impact of uncorrected refractive error as a leading cause of visual impairment and its economic implications, as well as the availability of corrective measures like glasses.

💡Optic Nerve

The optic nerve is the bundle of nerve fibers that transmit visual information from the retina to the brain. Damage to the optic nerve can result in vision loss or blindness. The video discusses conditions that affect the optic nerve, such as traumatic brain injury and diseases like glaucoma, and the challenges in detecting and treating these conditions.

💡Corneal Transplant

A corneal transplant, also known as a keratoplasty, is a surgical procedure where damaged or diseased cornea is replaced with healthy donor cornea tissue. This can be a treatment for conditions such as corneal blindness, which is often caused by infections or injuries. The video discusses the process and importance of corneal transplants, as well as the challenges in certain regions due to lack of donor corneas and the high cost of processing.

Highlights

Exploring the complex process of sight, from photons to visual cortex processing.

Understanding the anatomy and function of the eye, including lenses, photoreceptors, and neural fibers.

Investigating the global vision crises and its impact on productivity and personal well-being.

Technologies and methodologies for overcoming blindness and vision impairments.

The role of genetics and environmental factors in vision and eye health.

Advancements in treating age-related blindness and other degenerative eye diseases.

Exploring the implications of untreated refractive errors on global productivity.

Impact of corrective lenses on personal productivity and societal benefits.

Innovative treatments for macular degeneration and myopia.

Advancements in stem cell research for eye health and vision restoration.

The potential of optogenetics in treating retinal diseases and restoring sight.

Exploration of sensory substitution devices to provide experiences of the visual world.

Investigating the psychological and social aspects of vision loss and recovery.

The role of international collaborations and training in addressing global eye health issues.

Personal stories of overcoming vision loss and the importance of sight in human experience.

Transcripts

are you going to bug me i might get a

mug you it's that gorgeous one

and i believe i can run for decent

marathon

download

now

the americans have widened their

operation against rebel forces

the battlefield in fallujah is shrinking

we went to go check out our vehicle

stuck in the road

cleared it on the way back a daisy chain

the other one got me at the perfect

angle to launch in the air

i decided a long time ago that i've

always wanted to climb mount kilimanjaro

it was something that i wanted to do

with or without my disabilities

there are about 7.5 billion people who

live in this world and one third of them

it's 2.5 billion

are walking around the streets with poor

vision

sight is arguably our most important

sense an extremely complex process which

requires light that can start with

photons generated in distant stars

millions of light years away and end in

the visual cortex of our brains

in the middle of the process

our eyes

delicate orbs that are formed by

transparent and opaque structures micro

muscles lenses photoreactive cells and a

vast network of neural fibers that all

work in unison to transmit the data

carried by photons to our brain

this is a story about how our eyes and

our brains work to create the images of

the world in our head

and the science medicine and technology

that keeps them working for us

it also presents the quiet vision crises

that are taking place across the globe

and their enormous cost to global

productivity

from the many forms of age-related

blindness in the developed world to

blindness caused by myopic macular

degeneration in asia

and the cloudy visual world created by

cataracts across the equatorial regions

of the world

no one is exempt

just growing old is a risk to our site

then there are the forms of blindness

that a man made through accidents and

war

and the stories of the victims who

refuse to surrender to a world of

darkness

this is sight

the story

[Music]

the eyes

romantically called the windows to the

soul

lovers throughout history have held each

other's gazes from across a room

speaking volumes

without saying words

scientifically the eyes are extensions

of our brains designed to capture

photons and convert the information they

carry into an electric signal that the

brain can use

a lot of people think that a good

metaphor for the brain is a camera a

camera has a lens that focuses the light

that comes from the world it lands on a

sensor which converts that light into

electricity and get stored as digital

images and our brain is and our eyes are

much like that in a way so you have a

system of lenses the first lens is the

cornea where the light penetrates and

then it penetrates through the pupil

which actually has a diaphragm that

regulates how much

light gets into the eye and that light

allows the concentration and focusing of

the light to go through the crystalline

lens the crystalline lens is that very

peculiar structure in the eye and if you

remember the old

magnifying lens that would focus the

sunlight on a piece of paper well that's

exactly what the crystalline lens will

do it will focus the eye

back here on the retina the light has to

go through the entire retina

so the retina has to be transparent

and then it gets sensed at something

called photoreceptors our retina has two

types of photoreceptors called rods and

cones rods are sensitive to low levels

of light so actually when we're out at

night if you notice you don't see color

very well in the dark or in very dim

light and that's because the cones don't

have enough light to see and the rods

are the ones that are active cones

there's actually three types people call

them the short medium and long

wavelength cones which very roughly

correspond to red green and blue colors

different mixtures of those produce all

the different colors that we can see you

have the highest amount of cones in the

very central part of your vision exactly

where you're looking

and this allows us to perceive all the

rich colorful information that we get by

moving our eyes around and sampling from

place to place we have more rods in the

periphery

and this is the source of a common

phenomena that people can see when they

look outside if you look up in the dark

at the starlit sky

you often will see a dim star and then

you look at it you actually think that

it goes away and then you look a little

bit away from it and you can see it

again and this is because we don't have

rods in our central vision the

photoreceptors rods and cones react

differently to the photons striking them

but both are critical for our brain to

see the photoreceptors contain a

chemical that changes conformation

and that change in conformation uh is

what initiates the sensation of seeing

that signal goes from the photoreceptor

and then that photoreceptor is connected

at several different points to a set of

cells called bipolar cells

that bipolar cell then is speaking to a

retinal ganglion cell as its next

communication but before it goes to the

retinal ganglion cell it also splits off

and talks to other bipolar cells it

talks to multiple ganglion cells there's

all this crosstalk happening in the

retina and that's happening to process

the information that's being provided to

the body by that sensing of light the

function of the retina is to pre-process

information visual information so that

the brain can process it the retina

pulls information out of it it takes

what you need to know

and it ignores all the parts you don't

need to know and it like does data

compression and it converts that into a

code and then sends it up to the brain

and then the brain processes it further

the conversion and encoding of the

information carried by the light that

strikes the retina is very complicated

but the complexity of the process is

just beginning

the neurons that transmit the coded

electric impulses gather together at the

optic disk to form the optic nerve if we

look at the path of the optic nerve from

the top down

the fibers leave the optic discs as a

single bunch

when the nerve passes through the bony

optic canal and reaches the optic chiasm

the fibers divide into right and left

visual fields

the right field travels to the left side

of the brain while the left to the right

side of the brain this arrangement

provides our brain the ability to see

stereoscopically

but seeing by the brain is much more

complicated and this is where the camera

analogy breaks down we have a spot in

each of our eyes called the optic disc

where we have no neurons no

photoreceptors we actually can't see

what's there yet we don't have the

perception that there's a black hole in

our vision everywhere that teaches us

that really what our brains do

is they infer they make guesses another

example of the power of the brain's

ability to infer what we see is chris

raider chris is an iraq war veteran that

came home with post-traumatic stress

disorder that went undiagnosed when i

was in the marine corps i was in 0811

which is field artillery

i was the lead gunner of gun 4 for alpha

battery first battalion 10th marines

we went through the initial invasion i

had ptsd when i came back but it was

something that i didn't want to admit

that i had chris's untreated ptsd

eventually had catastrophic effects on

him it was june 7th of 2009

i did a poker run on my motorcycle and

on my race home i

did not make it and i woke up

three months later in a hospital

the police report states that chris hit

a car launching him into the air barely

missing another motorcyclist to land

with his motorcycle on top of him

engulfed in flames

in the accident i got a traumatic brain

injury or known as tdi

the doctors told my parents i would

never walk and talk again chris awoke

from his coma with damage to his optic

nerve of the optic chiasm i have a brain

injury with a vision loss from the optic

nerve the optic nerves one is on your

right side and one is on your left and

they cross fields like this

so my right optic nerve is gone so i've

got heminopsia which means the whole

left field is gone but chris's condition

went undetected because of the brain's

ability to infer what it is seeing there

is a condition called neglect

you've lost half of the vision in the

left eye corresponding half in the right

eye

and in neglect not only have you lost

the vision you don't know there is

anything there

it's it's a very

interesting condition from a research

point of view very frustrating to

rehabilitate because the person

you know may deny that they even have

the condition they retain 2020 visual

acuity so what could be wrong with the

visual system chris moved through the

veterans administration hospital system

and eventually ended up at their western

blind rehabilitation center in menlo

park california we had a tendency to

walk into the left side of doorways

or trip over things that were on his

left side i didn't admit i was blind i

would argue that you know it was

pointless

until i walked into a pole broke my nose

working with him

he was able to learn to scan to the left

bring his good area of vision into play

and walking through doors was no longer

a problem to better comprehend how the

brain can be retrained to see

we must understand how the signals from

the retina are distributed i study the

cerebral cortex or the covering of the

brain

which contains neurons that are

responsible for all sorts of higher

order functions in perception and

cognition our visual cortex actually

makes up more than half of our cerebral

cortex primates are very visual animals

there's more than 30 different regions

of the brain that are responsible for

different types of visual processing

these different regions of the brain

cross talk to build the images we see

all of the different regions of the

brain are actually communicating very

actively with each other all the time so

for instance if you need to know

where an object is to reach out to it or

to look at it you also might be at the

same time trying to know

which object to select from many and so

you really need to constantly have

communication between these different

brain regions that are constantly

updating and making guesses about what's

out there in the world sensing what's

there and helping inform your actions

the communication in the visual cortex

is not limited to data from the eyes

researchers at the university of

pittsburgh and fox center for vision

restoration are discovering that the

brain can see even without a signal from

the eyes we're encouraged by the fact

that we can do something called sensory

substitution

and still give people an experience of

the visual world that is not true visual

perception but it is a experience of the

visual world in terms of the visual

cortical neuroprosthesis our goal

is to be able to use technology that

would essentially plug directly into the

brain

and provide a true visual percept one of

these substitution devices is the brain

port the way the device works is that

a camera is mounted on a pair of glasses

and this camera inputs the visual

information

and turns it into an electrical stimulus

that's on a lollipop that you place on

the tongue we know that

when

patients

are presented with that information on

the tongue

who are blind

they use their visual pathways in order

to process that information there's some

plasticity

within the brain

that allows the information to be

processed in the visual system in people

who are

blind and

that happens

relatively quickly within days to weeks

of training with the device

it works much like the children's pin

impression toy but instead of pin the

device delivers electric stimuli to the

tongue we've done testing using the

device in an mri machine to see how the

brain lights up when non-seeing persons

are using the device the research has

discovered that the brain uses the same

regions in the visual cortex that a

sighted person would with their eyes

this phenomenon works not only with the

tongue-based brain port

but also a similar auditory-based system

it's the same locations whether you're

looking with the tongue-based device you

know presenting a video signal to the

tongue or if you're presenting the

visual information through an audio

signal the plasticity of the brain gives

researchers hope of finding ways to

overcome blindness by delivering signals

directly to the visual cortex blindness

however occurs in many different ways

along the optical and neural pathways

many of these causes have cures while

others remain elusive

in 2006 the world health organization

recognized that uncorrected refractive

error is the leading cause of visual

impairment in the world

so what is refractive error

eyeballs are not always perfectly shaped

when the eyeball is longer than the

focal length of the crystalline lens

then the individual is said to be myopic

or near-sighted

and if the eyeball is shorter then the

individual is said to be hyperopic or

sighted

both conditions cause blur rendering the

individual handicap from not being able

to see clearly close up or far away

the most important cause of vision

impairment is uncorrected refractive

error

it prevents children from learning

it prevents adults from working and it

prevents older people from enjoying the

quality of their lives

it seems so simple to those of us who

have the resources to get a pair of

glasses

many people underestimated the

importance of uncorrected refractive

error the world health organization

measure how your vision is when you

present to a clinic and that has made

uncorrected refractive error the leading

cause of visual impairment in the world

and the second leading cause of

blindness in the world

joseph is a young boy in mexico we're

seeing the world differently thanks to

his first pair of glasses

[Music]

is

[Music]

the number of individuals with

refractive error is significant

there are 37 percent of elderly

worldwide today that have uncorrected

vision

and associated with that are slips trips

and falls that can cost the medical

industry

uh billions and billions of dollars 30

of children today have uncorrected

vision the statistics are really

astounding there are about 7.5 billion

people who live in this world

and

one third of them it's 2.5 billion

are uncorrected and with their poor

vision

and this is huge this is probably one of

the biggest handicaps in the world

and you know out of the 2.5 billion we

believe that 80 of them which is about

2.2 billion live in emerging countries

it affects people economically in a

whole variety of ways for young children

it could affect their educational

attainment for adults in almost every

country it could affect their ability to

do work the cost to global productivity

due to uncorrected refractive error is

272 billion dollars per year now in a

world where we're talking about

trillions of dollars of global

productivity that doesn't sound like a

huge number but for the amount that it

would cost to fix the problem which is

only in the tens of billions would be

worth the investment if we could find a

way to corral those resources necessary

to build up the system it's much cheaper

for our world to actually address the

issue of uncorrected refractive error

than to leave intensities so thousand

factory workers 100 of them with the

problem you spend 100 per worker that's

a 10 000 investment if the factory is

producing a million dollars worth of

product a year and you can suddenly add

10 to that that's a hundred thousand

dollars return year on year for that

investment we examined about 300 workers

and then because they were very highly

unionized and are paid on productivity

they had excellent productivity recalls

which we had access to and that became

the baseline and then we gave them

glasses

we went back three months later we did

two assessments one we talked to the

patients to their wives and and overall

they were absolutely happy with wearing

the glasses the wife was saying the

husband is now more productive he's at

home he's reading papers he's not

running off from the house there was a

better marital harmony happening

and then on the factory side we looked

at the production records

there was a 13 percent jump in

productivity for a 10 investment so

subsequently when the management saw

this

they were literally forcing us to look

at all the 3000 employees

so because it's like a no-brainer the

reason vision care is important to

employers is it's a benefit first of all

that's highly valued by their employees

it's it's a fairly low cost but high

value benefit

you need to be able to see to do your

job you need to be able to see to be a

productive member of society healthy

eyesight is important to having a

fulfilling life and being productive at

work the refractive error is not only

limited to near or far vision

some individuals suffer from astigmatism

which is caused by an irregularly shaped

cornea crystalline lens or a combination

of both that produces two focal points

on the retina

individuals that have uncorrected

astigmatism have difficulty seeing fine

detail because the image they see is

blurry whether near or far

then there is the condition that

eventually affects most of us if we're

lucky to live long enough the

second major problem the human being has

had with vision

is called presbyopia presbyopia is a

major

scourge for people

the hardening of the crystalline lens

causes presbyopia

now when we're young this lens can

actually change shape it's very soft

and there's muscles in the eye that can

make this lens change the shape and by

doing that it can change the first focus

of the eye so we can see up close when

we need to or we can see into the far

distance if we need to

the problem is as we get older this lens

gets harder so it can no longer change

shape you can tell the age of a person

by when they need reading glasses

so if your friend pulls out a pair of

reading glasses

you know they're 45. presbyopia can be a

life-changing situation i've seen people

who go out of jobs because they don't

have

near vision and then when they go out of

job when they're 45 or 50 and they have

another 25 30 productive years ahead of

them it's very sad which can be simply

solved by a pair of reading glasses

glasses or spectacles are used to

correct the refractive errors that an

individual may have

eyeglasses have a rich history in form

and function and style

and in technology started in we believe

1286

it probably started from a magnifier on

a handle

some very clever lay person put two of

those together and join the tops of the

handles with a rivet

and you were able to hold them and look

through them

now that person probably wanted to keep

it secret make a profit from it

20 years later 1306

giordano di revolta

in a sermon they talked about eyeglasses

oki ali

brought to the world 20 years earlier

and this really changed a lot of things

and then by the time we have

guttenberg's press

and the demand for more ability to read

and the combination of spectacles

and printing changed literacy of the

world

and we see even through the 1400s

tens of thousands of pairs of eyeglasses

shipped from venice shipped from

florence all around the known world

so eyeglasses have a very rich history

and it started with someone's really

good idea although we think of glasses

as things that we

see with

but they have evolved to become a

fashion accessory

and therefore

people care almost as much as how they

are seen

or look with these devices as they are

looking through them we're in an

interesting industry because it combines

clinical with high fashion we help

people see but we also help them feel

better and look better and feel better

about themselves the fashion component

of vision correction is critical

you are going to wear a pair of glasses

and you want to look good in what you're

wearing and so we're really the only

part of healthcare that marries that

clinical aspect of taking care of your

eyes with a high fashion aspect of

looking good while you're doing that the

convergence of the medical necessity in

eyewear and fashion and trend

really started to take hold i would say

back in the mid 1900s with hollywood

actors and actresses using eyewear as

their fashion accessory and movies that

they were shooting one of the most

popular and well-known scenes is audrey

hepburn from breakfast at tiffany with a

classic wayfarer styling there's

probably not a movie today that you

can't watch that doesn't have a popular

either optical frame or sunglass that's

featured somewhere in the film that

really started a whole trend towards

emerging infusing the medical necessity

with the fashion world and bringing that

to the consumers today the old stigma of

being called four eyes is no longer a

part of mainstream society it has

changed dramatically number one

the i would call them ugly frames that

existed at that time

have undergone major overhaul so a lot

of design is now in a lot of fashion

that's number one number two i think

today for a lot of sports it's almost

becoming mandatory to wear eyeglasses if

you are in cycling or other sports where

you really like to have some protection

for your eyes be it normal sun lenses or

clear lenses or sport lenses or

corrective lenses so the stigma is kind

of gone there are many many examples now

of how acceptable it is to to need

glasses and we even see young people

today

buying optical frames

and not even needing a prescription but

just really wearing them to change the

way they're perceived by others glasses

have developed beyond simply correcting

vision

wearable technology allows the wearer to

collect data whether it's personal

biometrics or feedback based on their

location or activity this data can be

used to monitor a specific healthcare

issue or as a trigger in an early

warning system by utilizing an existing

aesthetic of the of eyewear you have the

opportunity to

at the same time that you're correcting

vision

you're also collecting a health aspect

of their data

and you're already in the clinical world

because you're taking care of vision

care which is part of a health record

so you're crossing all these different

boundaries at the same time advances in

eyewear are not limited to new digital

technology

with better understanding of light

science is reducing our health risk

brought about by modern technology we've

had all these new sources of

illumination enter our world backlit

screens on things like our televisions

our computers our tablets and our

smartphones the average person is

exposing themselves to devices four to

six hours a day well that's four to six

hours of hev light that you wouldn't

naturally have we're talking about the

wavelength of light between 400 and 500

nanometers so that encompasses blue

indigo and violet the shorter the

wavelength of light is the more energy

it has the more energy it has the more

damage it does to our tissues so we need

to attenuate that this blue light is

also affecting our sleep cycles we know

that digital eye strain has surpassed

carpal tunnel syndrome as the biggest

complaint in the workplace

we know that sleep disorders and

sleep-related disorders are on the rise

we know that there's a whole host of

broader health issues that are

increasing exponentially that can all be

traced back to the disruption of sleep

eyeglass manufacturers have solutions to

block this blue light much like they do

currently for ultraviolet there's two

main approaches to protective lens

products right now when it comes to blue

light the first approach is to create a

lens coating which will selectively

deflect blue light wavelengths off the

surface of the lens the second approach

is to infuse the monomer of the lens

with a dye or pigment which will help

absorb the blue light as it passes

through this blue light and uv

protection in eyewear is much like seat

belts in a car

they only work if individuals wear them

there's a heightened level of

sensitivity of awareness by consumers

today that you don't go outside when the

sun is shining without a proper spf you

certainly don't send your kids to the

beach without wearing sunscreen but it's

interesting to note that only 20

of children are protecting their eyes

from the harmful glare and rays of the

sun uv damage does a tremendous amount

impact the eyes at a very young age

about 85 percent of all the damage you

do is done before the age of 10 and that

exposure to uv can cause cataracts

a cataract is the clouding of the

crystalline lens that occurs with age a

long-term exposure to uv radiation our

lens filters out much of the blue light

and that's the reason we often develop

cataracts as we grow older because the

lens has been filtering out a lot a lot

of the bluer shorter wavelengths and

it's

virtually an inevitability of growing

older that we're going to develop

cataract in some form or another

worldwide 20 million individuals are

blind due to cataracts

the majority of those individuals live

in developing countries developing

country context

when one person is handicapped there's

at least another person has to give up

what they are doing to take care of this

person if somebody

can't see at all or can't see in any way

it's effective so they have two

cataracts then they are not socially

contributing and somebody has to stay

home and take care of them it's usually

a girl so the girl doesn't get to go to

school and so her life is blighted by

that absence of education and it

cascades through her family because she

hasn't had the education and you get a

cascading effect

from an avoidable issue that we could

solve so easily well cataract surgery is

the miracle of sight because it takes

patients who have slowly lost their

visual acuity

and

it restores vision often without the

need for glasses cataract surgery is the

most commonly performed surgery in the

united states so almost everyone knows

somebody else who has had cataract

surgery and virtually every cataract

surgery is a good experience we have the

ability now to pick an intraocular lens

that will correct refractive errors so

it's a fantastic operation it's

rewarding not only for the patient but

for the doctor because the patients the

next day actually see often perfectly

taking out a cataract and someone who

can't see

can turn their life around in 24 hours a

phenomenal 24-hour medical miracle

there are some countries where the

backlog of unoperated cataracts is huge

because there's no one around to do the

operation one method of overcoming the

deficit of surgeons in the developing

world is vision brigades that bring

qualified ophthalmologists to the

countries in need to perform the

surgeries we've been coming down to

honduras for the last 20 years or so

and

my goal for the country is just to do

what i can to get rid of the backlog of

50 000 people that are cataract blind in

this country the volunteer work that dr

kozawski and the other surgeons do in

honduras and in other developing

countries is humanitarianism

at its very finest

their efforts however are not enough

developing human resources in every

country and area in need

because the only way to solve the

problem is to train the people

who do the work in the societies to

advantage the people one organization is

doing just that orbis is a

non-governmental organization started in

1982 with the vision to prevent

blindness around the world the whole

idea was to

mobilize the training resources to the

eye care professional in their own

countries with their within their own

hospital with their own patients so

that's why the dc-10 was being a fully

equipped eye hospital self-contained

state-of-the-art facility it is not

about bringing some skilled surgeon who

can do hundred or thousands of surgery

it is about giving them the ability to

do

more surgeries after we leave and being

able to train their colleagues in the

future

this type of training provides the skill

set in each country to deal with ongoing

eye health care whether it is cataract

or other causes of blindness

the

corneal diseases are

quite common the cornea is that

transparent layer in front of the pupil

that protects the eye and forms the

first lens in the optical system of the

eye the transparent membrane is loaded

with nerve fibers and is the most

sensitive tissue in the body being 300

to 600 times the sensitivity of skin

due to its exposure to the environment

it's susceptible to injury and a variety

of diseases most of the corneal

blindness occurs in the developing world

for instance bacterial ulcers

are 10 times as common

in africa

compared to here

we live in

relatively clean countries

with

antibiotics antivirals antifungals

readily available

and

we don't have

that much problems with infections in

the developing world they don't have eye

banks

they don't have donor corneas

in addition it is very expensive for eye

banks to process because they have to

test for

hiv and

hepatitis and tb and all kinds of

diseases and conditions most of time an

eye bank will recover the cornea that's

the outer layer of the eye process it

evaluate it and make sure it's safe for

transplant and then we distribute it to

a surgeon an ophthalmologist trained in

corneal transplant surgery and they will

do the

transplant procedure we want to make

sure that the eye tissue that we provide

is safe for transplantation in some

cultures people feel that they need the

eyes to see god and therefore donor

materials are

non-existent

when we came and started high banking

everybody told me india i banking forget

it

nobody donates size

corneal transplants don't work in indian

ice

indian eyes are not suitable for corneal

transplant and today

we are one of the five biggest i banks

in the world

and perhaps the second largest corneal

transplantation center in the world

collaborative research between the

university of pittsburgh and the lv

prasad eye institute in india are

advancing the use of stem cell

transplantation to repair damaged

corneas

unfortunately we don't have as many

donor corneal tissues as we would need

so according to one recent estimate

of the eye bank association of india

there are around 140 000 cornea blind

individuals who are awaiting a corneal

transplant stem cells are harvested from

the patient and cultured for 30 days and

then used to promote restoration and

healing of the damaged cornea so we use

the patient's own cells

and after we have created this defect

we use the gel

which is basically a biological glue and

the stem cells are essentially laden in

this gel

so once the stem cells get incorporated

into the corneal stroma

they start to eat away the scars so they

slowly eat away the scar the cells the

stem cells that do all the magic are

basically from the same patient so there

is no chance that the patient in future

can reject these cells

and they have actually simplified the

technique from a very complex laboratory

oriented

technique into a simple in the eye kind

of technique

which any ophthalmologist in the world

can apply

at the completion of this procedure a

bandage contact lens is placed on the

treated eye to keep the gel securely in

place

contacts were originally developed in

the late 1800s to protect the cornea

from inward turned eyelashes a condition

called trichiasis

during the 20th century the contact lens

evolved to include refractive correction

45 years ago when contact lenses were

first commercialized

no one could imagine

the availability today

for just about anyone regardless of

their refractive error needs

real advantages for contact lenses are

that it doesn't change your natural

appearance

the the vision is clear

it's bright

it's natural you have a natural field of

view that's especially important in any

kind of sports activities or for example

when when driving the most important

steps

in

caring for contact lenses

is that just the proper hygiene of

washing hands

says it was from a contact lens she just

doesn't know when or how it started it

was very fast two days in

all corneas

contacts are safe and reliable but

proper sanitation habits are required

contact lens technology is moving

forward to be able to do biometric

measuring so that diabetics will no

longer have to

prick themselves or even use saliva

they'll be able to determine what their

glucose levels are strictly from their

contact lens that they're wearing and

contact lenses may have the same

technology embedded in them that google

glass has today using a prism we have

site recognition we have telescope

possibilities we have all sorts of

things when we put the lens on the eye

close to the pupil

nearer to the retina where we can

manipulate the optics and then combine

that with spectacles to create

systems of interaction

between spectacles and contact lenses

and vision so there's a massively

interesting future

in vision correction then we have drug

delivery possibilities and contact

lenses

a drug eluding contact lens could have

many uses

in theory it could be used to deliver

drugs to the body

the drugs would leak into the eye from

the contact lens and from the eye into

the rest of the body

but one of the great advantages is that

it would allow you to achieve very high

local concentrations of drug

in the eye

currently we are developing this contact

lens for use in glaucoma

because there's such a pressing need

glaucoma is the third major cause of

blindness around the globe

pass through heredity or when the eye

sustains an injury

untreated glaucoma can result in

irreversible damage to the optic nerve

it will destroy the optic nerve

it'll whittle away at it until you start

losing your peripheral field of vision

and it narrows down in a tunnel

fashion until you finally snuff it out

and you go blind what happens in the

various forms of glaucoma as we

understand it today is that a higher

than normal pressure presses on the

nerve and causes the nerve to slowly die

off over time normally your eye produces

a fluid in the eye called aqueous humor

which is produced inside the eye and

serves in many ways as the blood supply

or the oxygen supply to the clear

structures of the eye like your lens and

your cornea and that fluid is produced

and then drains out of the eye

continuously throughout the day

and you run into problems when the

natural drain can't keep up with the

amount of fluid that is produced and

when that happens the pressure rises

just like an overflowing bathtub when we

treat glaucoma we

generally try to lower the pressure as

much as possible to a range at which

that optic nerve is no longer continuing

to be damaged and we can do that

by

medications some of which reduce the

amount of fluid made in the eye

other medications enhance the flow of

fluid out of the eye and when those

things no longer work we go in and can

do surgery and generally the surgeries

that we do

either fashion a new drain

to bypass the dysfunctional one or we

enhance the drain that already exists

if you visited your doctor for an annual

or bi-annual eye exam

you've experienced the device that blows

a puff of air into your eye the device

is measuring the pressure of your

eyeball but there is more to the

detection and management of glaucoma but

when we're diagnosing dog glaucoma you

need to look at a lot of things the

first thing we need to look at are what

are your risk factors now age is the

major risk factor so glaucoma can affect

people of any age but normally it

affects people who are older so in

australia with a predominantly caucasian

population about three percent of the

people over the age of 50 have glaucoma

but if you look at people over the age

of 80 10 will have glaucoma

another very important thing is race we

know that certain ethnic groups are more

predisposed to certain types of glaucoma

then we look at your family history

which is critically important because

glaucoma is an inheritable disease

regardless of your family history or

race you should have your eyes checked

regularly not only for glaucoma but for

diseases that affect the retina

i'm a former truck driver

i'm recovering from a detached retina

i had

started

experiencing flashes

and a curtain coming in from the side of

my vision and it progressively got worse

until i experienced total blindness in

this eye

what happened to eddie is that the

vitreous humor pulled away from and tore

his retina the cavity

that we have in the posterior chamber is

known as the vitreous humor

now the victory is is a part of this

architecture or skeleton of the eye

but it also has the optical properties

because it's transparent and allows the

light to go through more frequently the

vitreous will separate

from the retina as we get older and then

we start seeing these little floaters in

front of our eyes that we follow and

they're still there these floaters are

actually the places where the vitreous

was adherent to the optic nerve the

macula or the retina periphery

in separation sometimes it'll tear the

retina

and if we do get a retinal tear we are

to get a retinal detachment

i went basically

nine days before i received medical

attention

by that time the destruction

in my eye was

quite severe

i've had a total of three surgeries now

part of the modern treatment of rental

pathology if there isn't here we treat

it with the laser to seal it and prevent

the detachment so if you seal the tear

with the laser before the retina

detaches that eye will go back to 2020

but if you detach the red and it's been

detached for two three months which is

typical in these third world countries

when in spite of the fact that you are

able to

reattach the retina visual acidity will

be very poor

they have no

idea how the recovery will

ultimately be

i've asked them several times

they just say there's no way of

guessing it

there are many conditions that can cause

the retina to succumb to damage and

failure so when the light rays come in

through the pupil they focus smack onto

the area of the retina known as the

macula and in the center of the

immaculate phobia is the most important

structure of the eye so most of the

visual acuity is focused in the macula

underneath the macula there's a pink

tissue known as the pigment epithelium

and macular degeneration is a

degeneration of the pigment epithelium

it's called amd or age-related macular

degeneration the important thing to know

about macular degeneration is it affects

the center of your vision so when you're

looking out with macular degeneration if

you're looking at someone's face you

can't see the most important details

their smile their nose their eyes and

you sort of see what's around me become

very debilitating and generally

immaculate degeneration affects both

eyes and so you're walking around with

just your peripheral vision in the

process of aging molecules

of this degenerative material known as

lipofusion accumulate in the pigment

epithelium and this material degrades

the quality of the rods and the cones

that are overlying

that alone reduces the visual acuity but

it also creates a window

through the pigment epithelium for blood

vessels to grow into the retina

and these are known as neovascular

membranes these membranes can bleed

and they can produce fluid and because

they are right below the phobia the

vision is greatly diminished there are

two forms of macular degeneration

wet and dry

the dry type is the more common type

there's different types but geographic

atrophy is the predominant type and

that's sort of the cells just go through

an aging process and they get worn out

the more devastating type to vision is

what's called wet macular degeneration

and that's when there's a break in the

membrane or the layer between the retina

and the choroid which is the

the blood vessels behind the eye and if

you get a break there you can get some

new blood vessels that grow in and

that's called exudative macular

degeneration when you get either blood

or fluid and that causes a very acute

massive drop in vision

i gave up playing cards because i

couldn't see the cards

and i gave up reading i just really went

to all audio books because i really

couldn't read well enough

fast enough to enjoy it

but each year it got worse

i saw less each year than i saw the year

before

dan was lucky enough to qualify for

unique implant made specifically for

macular degeneration the solution for

the

patient who has the amd

is

using the periphery of the retina and

bringing the image to places that are

not detected by the molecular

degeneration since the periphery is

resolution is not as good as a center

then we have to magnify the image

the telescope is doing this job once we

bring the

image to the delivery the patient can

gain

all the details the brain has to

accept these differences

in in the scene ability i

now can ski i can read or read on the

computer easily i can write letters i

can fill out checks fill out all kinds

of paperwork

with this

telescope because it makes things very

visible

it's amazing the telescope is a great

example of analog technology that is

being created to help aid amd patients

but researchers are hoping to stop the

degeneration completely with stem cells

advanced platform for the retina that

we're developing is a layer of stem

cells which is put on a synthetic

membrane

the advantage of this is that if you

just inject cells we believe that are

not in a sheet that are not oriented

properly the top side being the top and

the bottom side being the bottom then

they don't work as well so you can put

them in in a layer oriented properly

they'll function much better and that's

the premises of our approach these stem

cells would replace and take on the role

of the damaged photoreceptor cells

restoring the patient's vision

another form of macular degeneration is

quickly becoming the leading cause of

blindness in asia risk factor for myopic

macular degeneration is increasing

myopia and that's because increasing

myopia causes a lengthening of the

eyeball and when the eyeball lengthens

the retina is stretched and becomes thin

and damaged and even other parts of the

eye are affected primopia increases the

risk of cataract

at least three times

the risk of glaucoma

about five times

and not only that myopic macular

degeneration has been found to be the

number one cause of new cases of

blindness in shanghai china and also a

major cause of

blindness in japan

i would say myopia is epidemic in asia

in in school-aged children more kids

have it and the ones who have it have

more of it and if you think of myopia as

being ultimately associated with serious

comorbidities late in life so retinal

detachment glaucoma you're setting up

those children who have more severe

nearsightedness to be at risk for

potentially blinding eye diseases as

adults so what we have done is we've

looked at about 9 000 preschool children

children who are six months to six years

of age from four different racial ethnic

groups african-americans hispanics

non-hispanic whites and asians and what

we found was that the highest rates of

myopia nearsightedness were seen in

asians and in african americans

causes of myopia

are probably both

genetic and environmental it's very

clear that nearsighted parents tend to

have nearsighted children but this

increase in prevalence in the last few

decades

points to a strong environmental

component what we found was that the

amount of time the kids spent reading

doing homework watching tv using a

computer didn't affect their chances of

becoming nearsighted at all but what was

influential was how much time they spent

outdoors and what we found was that kids

who spent more time outdoors would have

a lower chance of becoming nearsighted

being outside was a good thing and so i

think schools need to

um enforce that if you will not have all

activities indoors but outdoors and in

open

sunlight where they can see things sort

of far away so that their eyes can begin

to actually change this drive which

occurs when they only

look at things up close earl smith at

the university of houston

does fundamental research

to show that you can slow the progress

of myopia

by manipulating the shape

of the image

that falls on the retina or its position

if you take a baby's eye

or a baby monkey's eye and you put up

a negative lens in front of the eye

and it pushes the image behind the

retina

the retina will keep growing

until it adopts the length

where it gets a clear image

and that's called

myopia

increase associated with

creating artificial hyperopia

or negative image behind the retina if

you put a positive lens up

and bring the image in front of the

retina then the eye growth will slow

all this work around vision by eye care

professionals technologists researchers

and doctors is to prevent blindness

blindness steals our ability to see the

beauty around us

the faces of our loved ones and shuts

off half of our brains resources

burns

coordinator reattachment retina

separated the explosion just

shredded my corny out of the place

afterwards i had a corny transplant

written reattachment from john hopkins

which is a top ophthalmologist clinic in

the u.s you can have a complete intact

eyeball

but if the nerves detach from the brain

that's a whole different story the 20

million dollar question science is how

do we get the brain to talk to the eye

the way it used to dr sheila nirenberg

of cornell has started to solve eddie's

20 million dollar question she and her

team have decoded the signal that the

retina sends to the brain and developed

a transmitter that generates the code

well the way we figured it out was we

took

normal animals and we presented them

with many different images and movies

and we recorded the responses of the

cells and the cell the responses are

electrical pulses so we had images

coming in on one side and electrical

pulses coming in on the outside

we just worked out the math to go from

input to output

so that we could put in completely new

images

and get the code

and make sure that

that it matches what the true code would

would actually be the transmitter that

generates the code will be paired with a

special type of protein that is

expressed into the damaged retinal cells

when a person has a retinal degenerative

disease the photoreceptors die and all

that circuitry next connected to it

starts to die too so you have the output

cells but you have no way of getting the

signals to those output cells because

it's all degenerative

so our device is basically jumping over

all that damaged area and interacting

with the output cells so that they can

send the signals to the brain

so then you need some kind of tool to

interact with those output cells and

make them do that job

so someone discovered this thing called

optogenetics it's a protein that's found

in algae and fungi it's a

light-sensitive protein you express it

into in a cell

and if you shine light on it it'll make

it send an electrical pulse

so if we know what the code is we can

send the code in light pulses and the

cell will respond by sending electrical

signals up to the brain currently in fda

trials this system may be the first step

in restoring sight to individuals with

retinal disease and damage like eddie

level

and eddie silva

it might also allow rebecca alexander to

see normally again i have something

called usher syndrome which means i'm

progressively losing both my vision my

hearing and more specifically the vision

part of my condition is called retinitis

pigmentosa rp and it generally affects a

larger population than usher syndrome

so if a normally sighted person can see

180 degrees when looking straight ahead

i have about 10 to 12 degrees of my

central most vision rebecca has slowly

been losing her sight along with her

hearing since she was a teenager i was

diagnosed with rp with the vision part

of what i have when i was 12

and then further diagnosed with usher

syndrome when i was 19. i'm 36 now and i

was told that by the time i was 30 i

would be completely blind

not willing to surrender to the darkness

just yet rebecca has recently completed

a lifelong goal we're in tanzania to

climb mount kilimanjaro

because it's been a goal of mine for a

while and i figured that

sooner would be better than later

given that my vision is not getting

better

if someone were to ask the question if

you had to lose either your vision or

your hearing which one would you choose

despite the fact that i'm losing both

hands down i would say i would rather go

deaf vision is such a hard thing to

navigate the world without

as human beings our sight will diminish

as we age and we will all face a vision

crisis

whether minor or total blindness like

rebecca prepares to face

when that time comes in our lives

technology science and medicine

will be there to minimize these crises

or completely restore our sight

guided by the humanity of those selfless

individuals that have dedicated their

lives so that others may see

[Music]

you