Eight hours of screen time has become normal. So have stinging eyes at the end of the day. This “digital eye strain” isn't a disease: it's the normal response of an eye doing the same thing for too long. The good news is that simple habits fix it.
Why your eyes get tired
Three mechanisms explain most of it:
- You blink less. In front of a screen, your blink rate drops by about half. The eye dries out, stings and turns red.
- You stare at a single distance. The muscles that focus the eye stay contracted for hours, like an outstretched arm.
- The lighting is badly set. A screen that's too bright in a dark room, or a window reflected in the display: the eye is constantly fighting the contrast.
The 8 habits
1. The 20-20-20 rule
Every 20 minutes, look at something 20 feet away (about 6 metres) for 20 seconds. It's the advice ophthalmologists repeat most, because it relaxes your focus. A discreet timer is enough to make it stick.
2. Blink, on purpose
It sounds silly. It works. When you feel dryness, close your eyes for two seconds, then blink slowly five times. If your eyes stay dry, preservative-free artificial tears from the pharmacy are a simple help.
3. Match the brightness to the room
Your screen should be about as bright as its surroundings. Quick test: look at a white page; if it looks like a light source, turn it down. If it looks grey and dull, turn it up.
4. Get rid of reflections
A window in front of or behind you reflects in the display. Turn your desk 90°, or lower the blind. Lenses with an anti-reflective coating help too: it's one of the real benefits of a pair like MIDI during the day.
5. Move the screen back
An arm's length away, with the top of the screen at eye level or slightly below. On your phone, hold it further away: 35 to 40 cm, not 20.
6. Make the text bigger
If you squint to read, the text is too small. Increase the system font size or the browser zoom. Nobody will notice — your eyes will.
7. Night mode after 8 pm
Most devices offer a mode that warms up colours in the evening. Set it to automatic. If you look at a screen late, an amber-tinted lens like SAFRAN filters even more — we cover this in our article on screens and sleep.
8. Get your eyes tested
A small uncorrected prescription is a common cause of fatigue and headaches. If the habits above aren't enough after two weeks, book an appointment. No pair of non-prescription glasses replaces an eye exam.
On your phone: three settings that change everything
Your phone is the screen closest to your eyes and the smallest — it combines all the worst conditions. Three settings, two minutes:
- Auto-brightness on, so the screen follows the room without you thinking about it.
- Text size raised by one or two notches in the display settings. Reading comfort is immediate, and you naturally hold the phone further away.
- Scheduled night mode from sunset to sunrise. Not because it “protects” you, but because a warm screen in the evening reminds you that it's late.
Signs that mean you should see someone
Eye strain goes away with rest. The following doesn't, and deserves a prompt appointment:
- blurred or double vision that persists after a night's sleep;
- daily headaches, especially at the end of the day;
- unusual sensitivity to light, a red and painful eye;
- dry eyes despite artificial tears, for several weeks.
Often the cause is a small prescription that was never measured, or dry eye that can be treated. In both cases, no pair of non-prescription glasses will change anything — and we'd rather tell you before you order.
And where do blue light glasses fit in?
They aren't the first lever — the habits above are. But an anti-reflective coating and, in the evening, a warm tint bring real comfort to many people. We explain frankly what the science says in this article.
Read next: Computer glasses: which ones should you choose? · Digital detox: 7 days to take back control of your screen time