Most of our computers, devices and applications offer this famous dark mode, but is it a fad, or a real revolution for our health? The answer lies somewhere between these two opposites.

In this article

  • what is dark mode

  • Dark Mode Has Real Benefits

  • Dark mode issues

Dark mode: origin and definition

Users of programming software, video editing solutions or even video games have long highlighted the importance of this feature to preserve their visual comfort and reduce eye fatigue.

For a few years now, the "dark mode" icon has appeared in the general public, we find it everywhere in the menus and the sidebar of our favorite applications and sites.

This is a button that allows you to change the white background to black, also adjusting the icons and the text on the screen.

gif presenting the activation of dark mode on iphone

📲 This feature allows us to change the display of texts on our smartphones and PCs from black on white to white on a black background .

Dark mode is better for the eyes in some cases

In theory, the advantages of dark mode are as follows:

  • 👀 Less eyestrain

  • 📖 Better readability

  • 🔋 Battery life optimization

  • 😴 Better sleep

Is this really the case? To some extent yes.

Dark mode is better for eyes in dark environment

In a study published by members of the University of Florida in 2019 that puts participants in the situation to test the dark mode against the standard mode, the conclusions are quite clear in a low light situation:

  • 📈 Better visual acuity, better readability

  • 📉 Significant reduction in eye fatigue

The study does not go into the detail of the physical mechanisms and it would therefore be interesting to dig into the mechanisms of the eye, undoubtedly at the level of the contraction of the pupil.

Zooming in on a screen in dark mode with one finger ready to click

The eye is made up of several layers and a muscle that allows more or less light to enter the retina. The pupil acts as a kind of blackout curtain that will open or close to let in a lot or little light.

Better sleep: decrease in the amount of blue light

Dark mode emits much softer, less harsh light and contains less blue light. The first effect of a reduction in this light is first of all additional comfort for the eye.

But the most interesting element is in terms of sleep, when we know that blue light prevents the production of melatonin , the hormone that allows you to get in condition for good sleep.

Your screen will still emit blue light (hence the importance of always wearing your blue light blocking glasses at night) but much less. You will therefore tend to fall asleep more easily.

Improvement for people with photophobia

Finally, the dark mode allows photophobic people to use screens like everyone else.

They are people sensitive to strong light (that of the Sun or screens that are too bright). This causes them migraines and other visual disturbances.

[Bonus]: Dark mode makes the battery last longer

Since the arrival of OLED screens , dark mode has been all the rage, as it increases the battery life of our smartphones and laptops. Indeed, OLED technology makes it possible to turn off pixels (rather than leaving them on and masking them as with LED technology), thus reducing the energy used.

This is also a feature implemented in basic OS like Android, iOS or Windows.

🔋 According to a 2021 study by Purdue University, if you keep your OLED phone's brightness level between 30-50%, you can expect 3-9% energy savings. If, on the other hand, your phone is always at 100% brightness, dark mode will save you around 39% to 47% of your battery!

Dark mode display: issues to consider!

Even though this feature is on all our devices, it's not a miracle solution to preserve your health. We must be careful not to activate it just because of our need for regular change (we would like to switch between dark mode and light mode to have the impression of using a new device each time).

☯️ The most important: the question of contrast

The effort required to look at a screen can vary greatly depending on your environment. In a dimly lit environment, where the main source of light is your screen, dark mode's darker colors may be perceived as less distracting.

Conversely, in a very bright environment, a darker screen can force your eyes to work harder.

Example of dark mode and light mode with two texts to illustrate readability

Your reading will be slower, you will strain your eyes more and you will tire more quickly. Also, if you are in an environment lit with LED bulbs, your retina will receive more blue light than it should.

To protect your sight and that your eyes do not strain too much, you need a lot of contrast and the dark mode does not provide this sufficient contrast in a well-lit environment.

In a bright environment, it is much easier to read black text on a white background , rather than the other way around.

Moreover, in case of visual impairment (myopia in particular), the dark mode of your smartphone is not ideal, because it makes the screen much less readable. However, 2.2 billion people in the world are visually impaired according to the WHO .

Take breaks and protect yourself from blue light

Dark mode won't solve all your vision problems!

The best way to rest your eyes is to avoid screens in the evening, take more breaks and think about getting some air!

This will allow them to reduce muscle tension, to find a more serene rhythm. And for those times when you really have to use a screen, don't hesitate to put on some good screen glasses that will help you fight digital fatigue. We also recommend that you activate the anti blue light mode on your device, whether it is a samsung , iphone or other device equipped with an LED screen.

The final word

If you want to take advantage of the screens of your devices, we recommend the dark mode for the eyes in a dark environment, provided you follow a few precautions:

  • Avoids dark mode in a bright environment,

  • Take breaks every hour;

  • Stay at least 50 cm from the screen;

  • Avoid screens before sleeping;

  • Wear blue light blocking glasses .

Screens are part of our lives, but you don't have to succumb to all the (dark) fads. The dark mode is to be used with caution, especially on your phone.

Tagged: Confort visuel