Dark Mode! Have As Many Advantages As You Think?

WhatsApp, Instagram and Twitter are just a few of the many applications that offer this option. Which is also available on the latest versions of iOS, Android and MacOS, among others. Dark Mode. Have As Many Advantages As You Think?

It is often said that it reduces eyestrain, makes reading easier and affects sleep.

There are several apps and operating systems that offer the dark mode: WhatsApp, MacOS, Android, iOS or Twitter, just to name a few.

This mode offers a dark screen background on which the letters become more yellow and pink, with less presence of blue. It is common to find information that says this is beneficial for many reasons, but is it really so?

Saving the battery.

Dark Mode. Have As Many Advantages As You Think?
Dark Mode.

The night mode helps us to save on battery power, but it should be noted that this is only valid for OLED displays the benefit is significant, because displays of this type are able to illuminate each pixel independently, but this does not happen with LCDs.

In those cases, even if half of the screen is shown in black, those pixels are also illuminated and therefore not as much battery is saved.

Tests were done with YouTube and it was found that on a smartphone with an OLED screen the device’s autonomy was between 14% and 60% higher when using the dark mode.

Variations depended on the type of content being played as well as the brightness.

Eyestrain is caused on the one hand by the reflex for near vision which consists of three issues: myosis, which is when the pupil gets smaller; convergence, which is when the two eyes come together to focus on a closer image and accommodation, which occurs when the lens increases its thickness when having a close image. This, coupled with the dryness of the eye caused by decreased blinking, leads to fatigue.

As mentioned here, the amount of light influences the pupil diameter so in the dark mode, the pupil remains larger and that is positive for eyestrain.

But that’s not the only factor, you also have to take into account the flicker and the fact is that when you’re exposed to the screen, regardless of which mode you’re set to, the flicker is less.

Fatigue can be caused by blinking less than normal when looking at a screen.

When we spend a lot of time in front of a display those 15 standard blinks per minute can drop to 3.6 when we look at a computer, tablet or cell phone, which contributes to dry eyes.

According to the American Optometric Association, symptoms associated with eyestrain can include headaches and blurred vision.

Reading texts.

Woman using mobile phone.

Numerous studies have referred to the contrast between objects and the background and how having a light background and a dark object or focus improves readability. However, it seems that this does not always work the same for all users.

In some cases it is easier to read when you see black letters on a white background because there is more contrast. It depends a lot on the age of the user and the particular case.

If you are a patient who has a decrease in contrast sensitivity such as with age-related macular degeneration or degenerative retinal disease or cataracts you may have more difficulty seeing when using the dark mode.


A video was viralized in which WhatsApp announced the arrival of the dark mode. This clip showed many people looking at their mobile phones in the dark and feeling annoyed.

What they saw were the effects of the glare that occurs when you are exposed to a very intense light source while in a very dark environment.

This contrast affects your eyesight and can be easily perceived when a car is driving on a road at night with very high white lights.

This produces that momentary blindness or glare. When we are in a dark environment our pupils are dilated to let in as much light as possible.

So, when a bright, intense light source suddenly appears, this problem occurs. The dark mode reduces the contrast in a space with low light and in this sense can be beneficial for the user.

In patients with good eye health a decrease in screen brightness, as occurs in the dark mode, reduces the risk of suffering from what is called digital eyestrain, which is a type of eye strain caused by the abuse of digital screens.


Dark Mode. Have As Many Advantages As You Think?

The dark mode reduces the exposure to the blue light of the mobile phone. That’s why this aspect is often seen as positive for improving your night’s rest.

A study conducted by researchers at the New York Light Research Center claims that artificial light causes the suppression of the secretion of melatonin, a hormone produced by the pineal gland that controls the sleep cycle.

In this sense, limiting exposure to artificial light, especially to the blue light that screens emit before going to sleep, is beneficial to health.

However, a new study by researchers at the University of Manchester concluded that blue light does not appear to be as harmful to our sleep patterns as previously thought.

According to these specialists, the use of dim lights and cooler shades at night, as well as using warmer lights during the day, can be more beneficial to our health. Experts believe that the sunset is darker and bluer than daylight.

Considering that the biological clock relies on these characteristics to determine what are the moments of wakefulness or sleep, then the use of blue during the night would be more beneficial than counterproductive.

“Our findings suggest that the use of dimmed, cooler lights at night and brighter, warmer lights during the day may be more beneficial,” Dr. Tim Brown, of the University of Manchester, explained in the journal released by the university.

Dark Mode. Have As Many Advantages As You Think?

In other words, for the same level of brightness in the display, the blue color produces greater relaxation than the yellow tones that are usually present in greater quantity in the dark mode than the former, which are actually reduced.

Another specialist noted that “there is a lack of evidence to justify or corroborate the effect of blue light on circadian cycles”. So for now, it cannot be confirmed that reducing blue light will necessarily favour the brain.

A sleep specialist at Michigan Medicine, explained that these conclusions should be taken with caution because they were reached after experimenting with rodents that are nocturnal and therefore may respond differently to light than humans.

The specialist also mentioned that the spectrum of light is not the only thing that matters: the brightness and duration of exposure to this type of light source must also be taken into account.

In addition, there is research that says that the use of electronic devices affects sleep whether they are used in dark mode or not, because it is an equal light stimulus.

At the same time, the cell phone is a stimulus for the brain that forces you to be alert and can generate stress, especially if you read emails or notifications that can generate concern or anxiety.

Damage to your eyesight.

There are studies, tested on animals (monkeys and mice), that conclude that exposure to blue light could present a risk for the development of macular damage or other retinal pathologies. The scientific evidence is still under discussion.