Dark or light mode: which is better for your eyes?

During the day and well into the night, people tend to stare at screens in one way or another, considering how they have dominated every facet of life. Staring at a screen isn’t a problem in itself, but if you do it for too long, your eyes start to become dry, tired, or irritated. It can go beyond that, with red eyes, text becoming blurry, the onset of headaches and even light sensitivity signaling one thing: digital eye strain (DES).

One way to combat this problem is to switch the theme of the device, app, or website to dark mode. Light mode places dark text on a light background, while dark mode does the opposite: light text on a dark background. It is supposed to be more comfortable to watch, preventing or reducing DES in the process. But unless you’re in low-light conditions, it’s not much better for you than sticking to light mode.

Neither mode is superior to the other, as it depends on the ambient lighting and the person’s vision. This last part is important because if you have eye conditions like nearsightedness (nearsightedness) and astigmatism, dark mode can actually make eye strain worse. Fortunately, there are ways to improve the lighting pattern for your eyes without purchasing blue light blocking glasses.

In low light conditions, your pupils dilate to let in as much light as possible. This is why looking at a screen for too long in bright mode with dim lighting can hurt your eyes. Brightness overwhelms your visual system, leading to the physical symptoms of DES. This is why dark mode works so well in these ambient conditions. By reducing the brightness, it decreases the contrast between the screen and the room, making your eyes more comfortable.

When you use dark mode in a well-lit room, your pupils dilate. Doing so reduces your depth of field, the distance at which objects appear sharper or more focused. This means your eyes will work harder to keep text sharp because of the reduced contrast. Sometimes this can make the text blurry or fuzzy around the edges.

This will affect nearsighted people the most, especially if they have astigmatism. Astigmatism is an imperfection in the curvature of the cornea or lens of the eye, which makes focusing difficult because light bends in different directions as it enters the eye. This creates multiple focal points instead of just one, leading to blurred or blurred vision. So, in addition to text looking less sharp, it may blend into the background due to dark mode, even when you’re wearing glasses. This will have a halo-like effect (halation), making it even more difficult to focus.

If dark mode is hard on your eyes, especially if you have low contrast sensitivity, you can still use light mode with some adjustments. On the one hand, you can try reducing the brightness so that the glare doesn’t hurt your eyes. However, you need to make sure it matches the ambient light around you.

For modern iPhones and some Android devices, you may not need to do this manually, as they have sensors that can detect the ambient light around you and adjust the brightness accordingly. This means that they will increase the brightness in a well-lit environment and decrease it in low-light conditions. Just keep in mind that turning off auto-brightness can extend your battery life. So be sure to do this manually – usually from the control panel – if you find that this is causing your battery to drain quickly.

Another thing you can do is enable Night Mode (Night Shift, Night Light, or Eye Comfort Shield). This places a warm, yellowish filter on your screen that reduces the amount of blue light emitted, making it easier on the eyes. Blue light is energizing and can suppress melatonin, the hormone your body produces to aid sleep. This is why you should never sleep with your TV on, as it emits the same type of light. Having night mode on an hour before bed can help you fall asleep faster.