How Do Our Eyes Really Work? (The Story of Vision) | Only Human
Summary
TLDRThe 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
👀 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.
👁️🗨️ 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.
🧠 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.
👓 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.
👵 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.
🌞 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.
🦋 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.
🛠️ 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.
🌐 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.
💡 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.
Mindmap
Keywords
💡Vision
💡Photoreceptors
💡Retinal Degeneration
💡Cataracts
💡Glaucoma
💡Myopia
💡Stem Cell Therapy
💡Visual Cortex
💡Refractive Error
💡Optic Nerve
💡Corneal Transplant
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
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