Why Dark Mode Reduces Your Productivity

Summary

The video discusses the pros and cons of dark mode in apps. It highlights that dark mode can extend battery life on OLED displays and reduce eye strain in low light, but may also decrease visual clarity, slow reading speed, and affect cognitive performance. The narrator suggests personal preference plays a key role in choosing between light and dark modes.

Takeaways

• 🔋 Dark mode can increase battery life, especially on OLED displays where black pixels don't consume power.
• 📱 For LCD displays, dark mode can still save power through local dimming, but the effect is less pronounced.
• 🌑 The power savings from dark mode can be minimal at default brightness but can be significant (39-47%) when brightness is at 100%.
• 👀 Dark mode is beneficial for reducing eyestrain, particularly in low-light conditions, by reducing the need for bright white pixels.
• 🌞 However, dark mode can also worsen eyestrain by causing a decrease in vision sharpness, known as the halation effect.
• 📚 Dark mode can negatively impact cognitive performance, slowing down reading speed and reducing the ability to spot spelling mistakes.
• 👓 Using dark mode with small font sizes can exacerbate the downsides, further reducing reading speed and increasing eye strain.
• 🌳 From an evolutionary perspective, our eyes are better adapted to spot dark objects against a light background, which is why dark mode might not always be optimal.
• 🏞️ The military uses this evolutionary trait in camouflage, highlighting the contrast between dark silhouettes and bright backgrounds.
• 💡 The choice between dark and light modes is largely a matter of personal preference, with some preferring dark mode at night and light mode during the day.

Q & A

What is the main benefit of using dark mode on devices with OLED displays?

The main benefit of using dark mode on devices with OLED displays is that it increases battery life because black pixels on an OLED display do not consume power.

Does dark mode save battery life on devices with LCD screens?

Dark mode does not significantly save battery life on traditional LCD screens because their power consumption is roughly the same regardless of the color of each pixel. However, modern LCD panels with local dimming can save some power in dark mode by turning off the backlight in zones that only contain black pixels.

How much power can dark mode save on devices at maximum brightness?

At maximum brightness, dark mode can reduce power consumption by 39 to 47%, which is a significant gain.

How does dark mode help in reducing eye strain?

Dark mode helps reduce eye strain by reducing the amount of bright white pixels, which can cause glare and make eyes feel tired more quickly, especially when using a device at night or in dimly lit rooms.

What is the halation effect and how does it affect readability in dark mode?

The halation effect occurs when white letters on a dark background appear blurry because our pupils open wider to let in more light, decreasing the sharpness of vision. This can make the letters bleed into the dark background, making them harder to read and increasing eye strain.

What impact does dark mode have on cognitive performance?

Dark mode can negatively affect cognitive performance, making reading slower and causing users to find fewer spelling mistakes when proofreading documents.

Why might dark mode be less effective with small font sizes?

Dark mode is less effective with small font sizes because it increases eye strain and reduces reading speed further. People often use small font sizes to fit more information on the screen, but this can be counterproductive.

What evolutionary context is provided to explain the disadvantages of dark mode?

Humans have evolved to hunt during the day, making our eyes adapted to spotting dark objects against a light background. This evolutionary trait explains why dark mode can make it harder to recognize shapes and read text.

How does the military use the evolutionary trait related to vision?

The military uses the evolutionary trait by advising against exposing oneself on a hilltop, as a dark silhouette can easily be identified against the bright sky.

What personal preference does the speaker mention regarding the use of light and dark modes?

The speaker mentions that they prefer using light mode during the day and dark mode at night, highlighting that the choice between light and dark modes often comes down to personal preference.

Outlines

00:00

🌙 Dark Mode: Advantages and Disadvantages

This paragraph discusses the pros and cons of using dark mode in apps. It starts by highlighting the common belief that dark mode can extend battery life, particularly on OLED displays where black pixels consume no power. However, this benefit is less significant for LCD screens unless they have local dimming technology. The script then points out that dark mode can reduce eye strain, especially in low-light conditions, by minimizing bright white pixels. On the flip side, dark mode can also increase eye strain and decrease visual sharpness, a phenomenon known as the halation effect. Furthermore, it is noted that dark mode may negatively impact cognitive performance, slowing reading speed and reducing the ability to spot spelling errors. The paragraph concludes by suggesting that the choice between dark and light modes is largely a matter of personal preference, with the speaker favoring light mode during the day and dark mode at night.

Keywords

💡Dark Mode

Dark mode is a display setting that uses a dark color scheme, typically with black or dark gray backgrounds. It is designed to reduce eye strain and save battery life on devices with OLED screens by reducing the number of light-emitting pixels. In the video, dark mode is discussed in terms of its potential benefits and drawbacks, including battery savings and its impact on cognitive performance.

💡OLED Display

OLED (Organic Light Emitting Diode) display is a type of screen technology where each pixel emits its own light, as opposed to relying on a backlight. This allows for true black colors and greater energy efficiency when displaying dark colors. The video highlights how dark mode can save power on OLED displays because black pixels use no power.

💡LCD Display

LCD (Liquid Crystal Display) is a screen technology that uses a backlight to illuminate pixels. Most LCDs consume roughly the same amount of power regardless of the color displayed, but modern LCDs with local dimming can save some energy by turning off the backlight in darker areas. The video contrasts the energy consumption of LCDs with OLEDs, noting the limited power savings of dark mode on LCD screens.

💡Local Dimming

Local dimming is a feature in modern LCD displays where the backlight is divided into zones that can be independently dimmed or turned off. This allows for better contrast and potential energy savings in dark mode by reducing backlight use in dark areas of the screen. The video explains how this technology enables some power savings even on LCDs when using dark mode.

💡Eye Strain

Eye strain refers to the discomfort and fatigue experienced by the eyes after prolonged use, especially under intense or poorly adjusted lighting conditions. The video discusses how dark mode can help reduce eye strain in low-light environments by decreasing screen brightness, though it can also exacerbate eye strain by making text harder to read due to the halation effect.

💡Halation Effect

The halation effect is a visual phenomenon where white text on a dark background appears blurry and harder to read due to the scattering of light, making letters bleed into the background. This effect can increase eye strain and reduce reading efficiency, as highlighted in the video when discussing the disadvantages of dark mode.

💡Cognitive Performance

Cognitive performance refers to the mental processes involved in gaining knowledge and comprehension, including reading, writing, and error detection. The video cites studies showing that dark mode can slow reading speed and decrease the ability to spot spelling mistakes, thereby negatively affecting cognitive performance during tasks like proofreading.

💡Brightness

Brightness is the level of light emitted by a screen. It plays a crucial role in eye strain and power consumption. The video discusses how adjusting screen brightness to match the ambient light can reduce eye strain, and how higher brightness levels can significantly impact the power savings offered by dark mode on OLED screens.

💡Battery Life

Battery life is the duration a device can operate before needing to be recharged. The video discusses how dark mode can extend battery life on devices with OLED displays by reducing the power consumption of black pixels. However, the effect on devices with LCD displays is less pronounced unless they have local dimming technology.

💡User Preference

User preference refers to the individual choices and habits of users regarding their device settings, such as the choice between dark mode and light mode. The video concludes by emphasizing that the decision to use dark mode or light mode often comes down to personal preference, with the narrator sharing their own habit of using light mode during the day and dark mode at night.

Highlights

Dark mode can increase battery life on devices with OLED displays because black pixels don't consume power.

For devices with LCD screens, dark mode's power-saving benefits are less straightforward due to the backlight illuminating the entire display.

Modern LCD panels with local dimming can save some energy by turning off backlight zones that only contain black pixels.

At default brightness levels, dark mode reduces power consumption by 3 to 9%, while at maximum brightness, it can reduce power consumption by up to 47%.

Dark mode can help reduce eye strain, especially in low-light conditions, by reducing the amount of bright white pixels on the screen.

Using a bright white screen in a dimly lit room causes glare and can lead to eye strain.

Dark mode's benefits for reducing eye strain are countered by the halation effect, where white letters on a dark background become blurry and harder to read.

Dark mode can slow reading speed and reduce the ability to spot spelling mistakes, affecting cognitive performance.

The disadvantages of dark mode are more pronounced with smaller font sizes, which increase eye strain and reduce reading speed.

Humans have evolved to see dark objects against a light background, which explains why light mode might feel more natural for reading.

The military uses the principle of dark objects against a light background for camouflage, avoiding exposing dark silhouettes against bright skies.

Despite its widespread adoption, dark mode has notable downsides and might not be suitable for all use cases.

Personal preference plays a significant role in choosing between dark mode and light mode, with some users preferring to switch based on the time of day.

Dark mode is popular, but its impact on productivity and eye strain varies depending on the individual's usage patterns and device type.

The video's discussion was inspired by a comment on the creator's use of light mode for coding, emphasizing personal preference in the dark mode vs. light mode debate.

Transcripts

Let’s talk about dark mode. Many apps  support it, but does dark mode have any  

advantages over light mode? Or is it just  a gimmick? Well, as always, the answer lies  

somewhere in the middle. So let’s start by  looking at the advantages of using dark mode.

The most commonly cited benefit is that dark  mode increases battery life. And that's true  

if your device has an OLED display. Black  pixels on an OLED display don't consume power,  

so more black pixels equals less  power. And when I say black,  

I really mean black. Dark shades  of blue or gray don't count.

And keep in mind, this is only for OLED  displays. If your device has an LCD,  

things get more complicated. Most LCDs have a  backlight that illuminates the entire display,  

meaning their power consumption is roughly the  same, regardless of the color of each pixel.  

So no battery savings from dark mode. Modern LCD panels have local dimming,  

where the screen’s backlight is split  into independently controlled zones.  

If a zone only contains black pixels, the  backlight can be turned off in that zone,  

saving energy. So dark mode does save  some power on modern LCD displays as well.

So how much power can dark mode really save? Some  websites say it uses 5 to 30% less power, but it  

actually depends on the brightness of your screen.  This study found that at default brightness  

levels, dark mode reduces power consumption by  just 3 to 9%. Barely noticeable. However, when you  

crank the brightness to 100%, dark mode can reduce  power consumption by 39 to 47%. A huge gain!

The second benefit is that dark mode  reduces eyestrain. Eye strain occurs  

when your eyes get tired from long intense use,  

like when driving long distances or staring  at a screen for long periods of time.

When it comes to displays, eye strain  is primarily caused by brightness,  

especially if that brightness is not adjusted  to our surroundings. See our eyes have adapted  

to look at things with equal brightness  compared to our surroundings. Using a bright  

white screen at night, in a dimly lit  room, will cause an irritating glare,  

and will make your eyes feel tired more  quickly. And looking at a dim screen  

during the day will require your eyes to work  harder to make out the letters on the screen.

So dark mode can definitely help reduce  the amount of bright white pixels,  

which reduces eye strain when using your  device at night or in dimly lit rooms.

But that's where the advantages end. Here are  two surprising downsides of using dark mode.

First up, while dark mode can reduce eyestrain,  it can also worsen it. A study from 2013 found  

that dark mode worsens your ability to recognize  shapes. When looking at a dark object or screen,  

our pupils open wider to let in more  light. That decreases the sharpness of  

your vision. White letters will  bleed into the dark background,  

making them blurry and harder to read. This  is called the halation effect. Your eyes will  

have to work harder to make out the letters  on screen, and that increases eye strain.

Blurry letters bring us to the most surprising  disadvantage of using dark mode. It affects our  

cognitive performance. One study found that  you’ll read slower while using dark mode,  

and if you’re proofreading a document,  you’ll find fewer spelling mistakes.  

So better switch to light mode when  writing an important email to your boss.

Another study found that the downsides of dark  mode are even worse when you use small font sizes.  

And yet, that's what many people do. We tend to  use small font sizes to cram more information  

on the screen, making us feel like we're more  productive. But actually the opposite is true.  

By reducing font size we reduce our reading  speed and increase eye strain even further.

These disadvantages might come as a  surprise, but from an evolutionary context,  

they make a lot of sense. Humans  have evolved to hunt during day,  

so our eyes are adapted to spotting  dark objects against a light background.

The military uses this evolutionary  trait to their advantage. The golden  

rule of camouflage is to never ever  expose yourself on a hilltop because  

your dark silhouette can easily be  identified against the bright sky.

So there you have it. Dark mode  is being adopted everywhere,  

but it’s not without downsides. It can  both increase and decrease eye strain,  

it slows your reading speed and it  affects your cognitive performance.

If you want to support this channel, consider  signing up for my newsletter to get a monthly  

dose of science and technology news. Last  month, I wrote about how New York is sinking  

because of the weight of all the buildings and  how scientists harvest electricity from the air…

Oh, and this video was inspired by  someone calling me a freak for using  

a light color theme while coding. In the  end, I think it’s all about preference.  

I enjoy using light mode during the day  and dark mode at night. But then again,  

bugs are attracted to light, so maybe I  should only use dark mode when coding...

Thanks for watching, and till next time!