Why dark mode isn’t good for your eyes?

Dark mode is probably one of the most popular features of modern user interfaces. From apps to operating systems, from Apple to Google, smartphones to laptops, many of the products we use today have some sort of dark mode built into the user interface.


Did you know that dark mode is not really a modern invention? And did you know that there are downsides to switching your apps to dark mode?

History of dark mode

Millennials may be unrelated, but some of the first personal computers to use monochrome CRT displays displayed green text on a black screen. Many of the first word processors (yes, there are ones dedicated to what you can do in Microsoft Word) also allowed typing in white text on a black background.

dark mode


That all changed in the 1980s, when companies like Xerox and the now-defunct CPT Corporation created word processors that had a white screen with black text. This is done to reproduce the appearance of the ink on the paper.


Fast forward a few decades and Dark Mode is back. Companies like Apple and Google have announced a lot of dark themes for all their products, and the world has followed suit.

Dark mode- advantages and disadvantages

Advantages

The most well-known and scientific benefit of dark mode is that it saves power on devices with OLED or AMOLED screens.


On an OLED panel, each pixel is individually illuminated. When the background is white, all the pixels are on and the screen requires more power. When the pixels are black or even dark gray, as is the case in dark mode, the display’s power requirements are naturally reduced.

dark mode


This dark mode power saving is limited to OLED screens, so phones, monitors and laptops with LCD screens don’t really benefit. This is because the LCD screen is illuminated with the help of the rear panel which is always fully lit.

Disadvantages


Businesses often make general statements about how darkness improves visibility, reduces eye strain, and makes it easier to use devices in low light. But that’s not always the case.

The most well-known and scientific benefit of dark mode is that it saves power on devices with OLED or AMOLED screens.


On an OLED panel, each pixel is individually illuminated. When the background is white, all the pixels are on and the screen needs more power. When the pixels are black or even dark gray, as is the case in dark mode, the display’s power requirements are naturally reduced.


This dark mode power saving is limited to OLED displays, so phones, monitors and laptops with LCD screens don’t really benefit. This is because the LCD screen is illuminated with the help of the rear panel which is always fully lit.


That said, a recent study has suggested that you only really save a lot of power if you switch from light mode to 100% brightness. The researchers found that switching to dark mode from low to medium light only saved 3-9%.


Another use of dark mode that we often hear about is that it cuts out harmful blue light. Blue light is the shortest wavelength high-energy visible light spectrum. The biggest natural source of blue light for humans is the Sun, but our phones also emit traces of blue light.


According to a Harvard Health article, overexposure to blue light can suppress the secretion of melatonin, a hormone important for a good night’s sleep. However, it’s really not something you should worry about!
Businesses often make general statements about how darkness improves visibility, reduces eye strain, and makes it easier to use devices in low light. But that’s not always the case.

Astigmatism

astigmatism

According to the American Optometric Association, a condition called astigmatism is very common in people. The Schaeffer Eye Center writes that nearly 30% of different population groups suffer from different degrees of illness. Astigmatism causes blurred vision due to the irregular shape of one or both eyes. This can make it difficult to read bright text on a dark background. The 2014 Gizmodo article cites the Sensory Perception and Interaction Research Group at the University of British Columbia:

People with astigmatism (approximately 50% of the population) find it harder to read white text on black than black text on white. Part of this has to do with light levels: with a bright display (white background) the iris closes a bit more, decreasing the effect of the “deformed” lens; with a dark display (black background) the iris opens to receive more light and the deformation of the lens creates a much fuzzier focus at the eye.

You may have astigmatism and may not even know it. While you can ask your optometrist to check this, this could be the reason why you feel uncomfortable reading content on your phone with dark mode enabled.

Problem with dark mode

Black text on a white background offers the best readability, hence best intelligibility and retention. Why? Because white reflects all wavelengths of the visible spectrum. The iris does not need to be widened to absorb more light. When you see clear text on a dark screen, its edges seem to blend into the black background.


Since the iris doesn’t widen when looking at a white screen, the pupils remain narrow and you have to work less hard to focus on things. When you see contrasting black text on a white background, you can immediately focus on it.


In dark mode, your pupils dilate to let in more light. When you see clear text on a dark screen, its edges seem to blend into the black background. This is called the halation effect.


Remember, the eye is made up of muscles. The more you force it to try to read something, the more it wears out. If you don’t feel comfortable reading light text on a dark background, don’t force it.

Blue Light

The same Harvard article on the harmful effects of blue light also talks about the benefits of exposure to it. The article explains that blue wavelengths are beneficial during the day because they help improve mood.
Doctors from the American Academy of Ophthalmology also believe that healthy exposure to blue light can maintain mental performance and reduce myopia in children.


There is no scientific evidence that blue light from devices is harmful to the eyes.


While it may be beneficial to eliminate screen glare at night when the overall environment is dark, it may not be good to keep these pixels off all the time.


There is also no scientific evidence that blue light from devices is harmful to your eyes, nor is there enough research to show that dark mode allows you to see better. In fact, researchers suggest that the discomfort people experience after staring at screens for too long is due to less flicker than to brightness.


Ultimately, everyone’s experience with Dark Mode is different. A lot also depends on the ambient light in which you use your monitor.


While dark themes may be more suitable for the night, they don’t necessarily help you read better or save your eyes from digital fatigue, or even save a lot of water on your device .

You can also avoid dark mode altogether if you start to notice problems with your vision or increased sensitivity to light.


Are you in dark mode or are you staying away? Let us know!

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