Glasses with a blue-light filter are sold as a solution to the problem of tired eyes, and a significant part of people who spend the day in front of a monitor are convinced of this. Research does not confirm this belief, and the reason is that the problem has a completely different origin.

What the Systematic Review Showed

A 2023 Cochrane review, prepared by researchers from the University of Melbourne, summarized seventeen randomized controlled trials involving more than six hundred people. The conclusion is that glasses with blue-light filtering probably make no difference either to eye fatigue from working at a computer or to sleep quality. The researchers also found no evidence that such lenses protect the retina from damage. The American Academy of Ophthalmology, in its position, directly states that there is no scientific basis for special glasses for working at a computer. The most illustrative thing in this topic is a comparison of scales. One of the review's authors points out that the amount of blue light our eyes receive from artificial sources such as screens is approximately one thousandth of what we receive from daylight.

That is, by going outside on a sunny day, you receive a thousand times more of the same radiation from which glasses supposedly protect you indoors.

What Actually Tires the Eyes

Disruption of the tear film. Working with a screen changes the way you blink, and this is what dries out the surface of the eye. There is an interesting nuance here that changes the usual explanation. For a long time, it was believed that people simply blink less often when looking at a screen. Studies show that the blinking frequency when working at a computer and when reading printed text differs only slightly, approximately fifteen times per minute versus almost fourteen. What gets worse is not the frequency, but the completeness of blinking. In front of a screen, a person blinks incompletely, meaning the eyelid does not close all the way, and the tear film is not distributed properly over the surface of the eye.

Focusing strain. Long-term work at a close distance requires constant effort from the muscles responsible for focusing and for bringing the eyes together, and it is this muscle strain that gives the feeling of fatigue.

Conditions around the screen. Reflections, poor room lighting, an unsuccessful monitor position, and a mismatch between the brightness of the screen and the room add strain regardless of everything else. A separate reason that is often overlooked is outdated vision correction. Incorrect glasses, uncorrected astigmatism, or lenses not designed for the intermediate distance to the monitor create constant strain that no filter will remove.

What Works

The twenty-twenty rule is applied first, since this is exactly what the American Academy of Ophthalmology recommends as the main response to this problem. Every twenty minutes, look at something approximately six meters away and keep your gaze there for twenty seconds. The mechanism here is twofold, since looking into the distance relaxes the focusing muscle, while the pause itself encourages complete blinking. The advice looks primitive precisely because it is simple, and most people do not follow it. A timer or reminder in the system helps. Blink consciously while working, since the problem is specifically incomplete blinking. Several times an hour, it is worth making several deliberate, complete blinks, with full closing of the eyelids. Adjust the screen brightness to the room lighting, that is, so that the screen is neither noticeably brighter nor noticeably darker than the surrounding space. Remove reflections by positioning the monitor so that the window is to the side, not behind you and not opposite you.

Place the screen at the correct distance, that is, approximately at arm's length, and so that the upper edge of the screen is slightly below eye level. Looking slightly downward reduces the area of the exposed surface of the eye and slows tear evaporation. Increase the text size instead of leaning toward the screen.

Ventilate the room and monitor the humidity, since dry air, especially in winter when the heating is running, noticeably increases symptoms. Check your vision correction, since for many people this turns out to be the real cause.

About Sleep and Evening Screens

The situation here is more complicated than in the case of daytime fatigue, and it is not worth unequivocally denying the effect.

Blue light in the evening really does affect melatonin production, and in studies it suppressed it noticeably more strongly than green light of the same brightness, shifting the internal clock by hours. But this does not mean that glasses are beneficial, since the same Cochrane review also found no effect from them on sleep quality. The practical solutions here are different, namely reducing the screen brightness in the evening, using night mode, and most importantly reducing the use of devices itself before going to bed. I wrote about tools for this in the material about screen time.

When It Is Worth Seeing a Doctor

The measures described concern ordinary fatigue from prolonged work with a screen. If the symptoms do not go away after rest, persist constantly, or are accompanied by worsening vision, pain, double vision, redness, or light sensitivity, this is a reason to see an ophthalmologist rather than look for everyday solutions. The same applies if you have not had your vision checked for a long time, since an examination here gives more than any advice from the internet. Regarding moisturizing drops, it is worth consulting a doctor or pharmacist, since they differ in composition and are selected for a specific situation.

Is It Worth Buying Such Glasses at All?

These glasses are not a scam, and they do not harm anyone, it is just that the marketing promises around them significantly exceed what the studies show. If you subjectively feel more comfortable in them, you can use them, but you should not rely on them as a solution to the problem, and it is wiser to invest money in something else, that is, in having your vision checked, in proper workplace lighting, and in the habit of taking breaks.


Sources

Cochrane Database of Systematic Reviews (2023), review of blue-light filtering lenses, University of Melbourne. Position of the American Academy of Ophthalmology. Publications by Ophthalmology Times