So blue light glasses are useless?

Not useless, just oversold. They do not prevent eye damage and the evidence for that claim is weak. Some patients find them subjectively more comfortable, and evening use has a defensible sleep rationale.

Why do my progressives not work at my desk?

The intermediate zone in a general progressive is a narrow band, so you tilt your head back to find it and hold that position. An office progressive gives a much wider intermediate field and is a common second pair.

Does digital eye strain cause permanent damage?

No. Symptoms resolve when the cause is addressed. The one caveat is that untreated chronic dry eye can cause lasting surface damage, which is a reason to have it assessed.

Digital Eye Strain: It Is Not Blue Light

By Dr. Mark Page · August 12, 2026 · 3 min read

Blue light filtering is one of the most successfully marketed products in optics. It is also one where I have to give patients an answer they do not expect, because the research does not support the main claim being made for it.

That does not mean the discomfort is imaginary. Digital eye strain is real, extremely common, and treatable. It is simply caused by something else.

What actually causes it

Two mechanisms, both mechanical and both unglamorous.

The first is sustained accommodation. Focusing at near is muscular effort, and holding one distance for hours without relief produces fatigue in exactly the way holding any muscle contracted does.

The second is blink rate. During concentrated screen work your blink rate falls by roughly two thirds, and many of the blinks you do manage are partial, which do not resurface the tear film. Your ocular surface dries out. In Phoenix, with single-digit humidity and air conditioning running, it dries out faster.

Where the blue light claim stands

The concern originates in laboratory studies showing that very high-intensity blue light can damage retinal cells. That is true, and the intensities involved are far above anything a screen produces.

For scale: sunlight delivers vastly more blue light than any monitor. If screen blue light at typical viewing intensities damaged the retina, going outside would be considerably worse.

What can be said fairly is that some patients report genuine subjective comfort improvement with a filtering lens during long sessions, and that is worth something. There is also reasonable evidence that evening blue light exposure affects sleep timing, so filtering for evening screen use has a defensible rationale.

So we fit them if you want them, at a fair price, described accurately. We will not tell you they prevent eye damage.

The lens that actually helps

Your distance glasses are optimised for far vision. Your reading glasses are optimised for about forty centimetres. A monitor typically sits at sixty to eighty, which is precisely the range neither handles well.

For patients under forty, a single vision lens set to measured screen distance, sometimes with a small relieving power, frequently resolves the complaint outright. For presbyopic patients, an office progressive with a wide intermediate zone is transformative compared with fighting a general progressive's narrow intermediate band.

The key word is measured. We measure the distance to your actual screen rather than assuming a standard, because desks vary enormously.

The dry eye connection people miss

A large share of what patients call eye strain is dry eye triggered by reduced blinking. The symptoms overlap almost completely: burning, grittiness, blur that clears briefly when you blink, heaviness by late afternoon.

If that describes you, no lens fully solves it, because the lens is not the problem. We assess the tear film at the same visit, and treating the dry eye is frequently what actually resolves the complaint.

Changes that cost nothing

Position the monitor so the top of the screen is at or slightly below eye level. Looking slightly downward is the eye's most relaxed position and exposes less surface to the air.
Keep the screen at roughly an arm's length.
Twenty-twenty-twenty: every twenty minutes, look at something twenty feet away for twenty seconds.
Blink deliberately and fully. Partial blinks do not resurface the tear film.
Move air vents away from your face. In an Arizona office this is one of the highest-impact changes available.
Reduce glare rather than increasing screen brightness. Avoid a window directly behind or in front of the screen.
Match screen brightness to the room instead of running it at maximum.

When it is worth an exam

If workspace changes have not helped, if you are getting headaches, or if text sometimes doubles, it is worth being examined. Two treatable causes hide behind the digital eye strain label: untreated dry eye, and binocular vision problems such as convergence insufficiency.

Both are common. Both are fixable. Neither is addressed by a filtering coating.

The short version

Digital eye strain is caused by sustained focus at one distance and a blink rate that drops by roughly two thirds.
Sunlight delivers vastly more blue light than any monitor. The evidence that screen blue light damages the eye is weak.
Blue light filtering is fine to have for comfort or for evening screen use. It is not a medical necessity and should not be sold as one.
A lens set to your measured screen distance frequently resolves the complaint outright.
Much of what is called eye strain is dry eye triggered by reduced blinking, and no lens fully solves that.
The free fixes are real: monitor height, screen distance, twenty-twenty-twenty breaks, deliberate blinking, and moving the air vent.

Want the full detail?

Read about computer glasses

This article is general educational information, not medical advice or a diagnosis, and it is not a substitute for an examination. If you are experiencing sudden vision loss, eye pain or an eye injury, contact us immediately or go to an emergency room.

Digital Eye Strain Is Not About Blue Light