Eye Strain and Blue Light: What Actually Works

What the Eye Doctor Said

Last October I went to the eye doctor, and he said I had "dry eye syndrome and severe accommodative muscle fatigue." When I told him I spend over 12 hours a day looking at screens, he just went "well, that's..." and trailed off. Got prescribed artificial tears and left, but a month later nothing had improved, so I started looking into solutions on my own.

Blue light blocking glasses, monitor films, dark mode, the 20-20-20 rule. I tried them all.

The Truth About Blue Light Glasses

I bought a pair of blue light blocking glasses for 38,000 won. Bottom line: virtually no noticeable effect. I wore them for about two weeks and couldn't feel any reduction in eye fatigue.

I later learned that the evidence for blue light being the main cause of eye strain is actually weak. The American Academy of Ophthalmology doesn't even recommend blue light glasses -- which I found out too late. (There goes 38,000 won.) The real cause of eye strain is simply staring at something up close for extended periods.

Monitor Brightness Was the Key

Surprisingly, the most effective change was adjusting my monitor brightness. The office lighting was bright, but I'd been running my monitor at 100% brightness. When I matched it to the ambient lighting, my eyes noticeably hurt less. Dropped brightness to 65 and bumped contrast up slightly.

But I made a mistake here too -- at one point I dropped brightness all the way to 30. Couldn't read the text properly, ended up squinting, and my eyes actually got more tired. There's a sweet spot; just lowering it as much as possible isn't the answer.

The 20-20-20 Rule Is Perfect in Theory

Every 20 minutes, look at something 20 feet (about 6 meters) away for 20 seconds. I'll be honest -- I know this works. But execution is the problem. When you're deep in code, 20 minutes flies by, and even when the timer goes off, you think "hold on, let me just finish this" and ignore it.

I actually did it diligently for three weeks. Then a deadline hit and the whole thing collapsed. Now I've compromised by looking out the window during Pomodoro breaks. Not perfect, but better than nothing.

The Right Way to Use Artificial Tears

At first I only used them when my eyes felt gritty. Two or three times a day. The eye doctor told me to "use them regularly before they get dry," so I bumped it up to six times a day, and there was a clear difference. The preventive approach was the right call.

Apparently it's important to use preservative-free single-use vials. I initially bought cheap ones from the pharmacy that had preservatives and used them for two weeks before the doctor told me to stop. Single-use artificial tears run about 12,000 won per box. Two boxes a month is 24,000 won.

Monitor Distance and Height

My monitor was 45cm away. I pushed it to 65cm. For a 27-inch monitor, the right distance is supposedly about arm's length -- where your fingertips touch the screen with your arm extended. I also adjusted the monitor arm so the top of the screen was at or slightly below eye level. Looking upward apparently dries your eyes out faster.

Moving the screen farther away made text look small, so I bumped up my IDE font size from 14 to 16. A coworker asked "why is your font so huge?" but eye health matters more.

Current State After a Year

If I had to rank what worked: monitor brightness adjustment is number one, regular artificial tear use is number two, and increasing monitor distance is number three. Blue light glasses and dark mode had almost no noticeable effect, honestly.

When I went back to the eye doctor, he said "things have improved a bit." But it's not fully resolved. As long as I'm looking at a screen 12 hours a day, I don't think there's a fundamental fix. It's about managing it as you go.