Eye Strain Headache From Screens and Glasses: Test It in a Week
If your headache sits across the forehead or behind the eyes, arrives after an hour or two of screen or book, and is gone by the time you wake up, your eyes are the likely cause. You can test that at home in seven days without buying anything: fix the screen, take the breaks, and see whether the headache follows. If it doesn’t budge, the fix is usually an eye test and the right number, and this guide tells you which.
The short version
- Typical eye strain headache: dull ache across the forehead, temples or behind the eyes, worse late in the day, better after sleep, often with tired, dry or watery eyes and blurred focus when you look up.
- Three causes: screen habits (distance, height, brightness, no breaks), an uncorrected or out-of-date glasses number, and dry eyes from blinking less.
- The week test: change the setup and the breaks for 7 days; if the headache falls by half or more, it was the setup. If not, book an eye test.
- Not eye strain: a headache with nausea and light sensitivity, a one-sided throbbing headache, a headache every morning, or any red flag below.
Prefer to listen? This post as a 2 min video · Watch the video
How to know it’s your eyes and not something else
Eye strain (asthenopia) is the focusing muscles inside the eye, and the muscles that turn the eyes inward, working too hard for too long. A phone at 25 cm keeps them contracted for as long as you hold it there. After an hour they tire. After three they ache, and that ache is what you feel as a headache. The tell-tale features: it builds during close work, it never wakes you, it is on both sides, and the eyes themselves feel gritty, heavy or unfocused when you finally look across the room.
Two other headaches get blamed on eyes and are not. Migraine brings nausea, light and sound sensitivity, throbbing and sometimes a visual aura, and while a screen can trigger it, new glasses will not stop it; tension-type headache feels like a tight band and belongs to the neck, stress and posture. Different causes, different fixes. If your headache has those features, the headache home remedies and when to worry guide is the better read.
Some headaches must not be put down to screens at all. A sudden severe headache that peaks within a minute, a headache with fever and a stiff neck, one that follows a blow to the head, one with weakness, confusion, double vision, speech change or loss of vision, a new headache after 50, a headache in pregnancy with swelling or high BP, or a child’s headache with vomiting or waking from sleep. Any of these means a doctor today or emergency care now, whatever your screen time.
The seven-day eye strain test
Do all of these for a week. Half measures will not tell you anything. Keep a note each evening of whether you had a headache, when it started, and how bad it was out of 10.
- Distance. Push the monitor to arm’s length, 50 to 70 cm from your eyes. Hold the phone at 40 cm, not 25. If text is too small at that distance, enlarge the font rather than leaning in.
- Height. The top of the screen at eye level or a little below, so you look slightly down at the middle. Laptop on a bed or lap means a chin on the chest and eyes rolled up; raise it on books and use a separate keyboard if you can.
- Brightness. Match the screen to the room. Hold a white sheet of paper next to the screen: if the screen glows brighter than the paper, turn it down. Full brightness in a dim room is a headache recipe.
- Glare. No window directly behind the screen or behind you; turn the desk 90 degrees to the window or draw the curtain. A tube light reflected in the screen counts too.
- Breaks. Every 20 minutes, look at something 6 metres (20 feet) away for 20 seconds. Set a timer for the first three days; you will not remember on your own. Our 20-20-20 habit post covers how to make it stick.
- Blink. Screen users blink about a third as often as normal. During each break, close the eyes fully for a slow count of five, twice. If your eyes feel dry, lubricating eye drops from a pharmacy, used as the pack says, are fine.
- Text size. Set fonts so you can read comfortably at arm’s length. On a phone, increase the display size in settings; on a computer, zoom the browser to 110 or 125 percent.
- Night. No screen in the last 30 minutes before bed, and dim the room lights in the evening. Tired eyes at 7 am mean tomorrow’s headache starts earlier.
By day 4 or 5, a genuine setup problem shows a clear improvement, and by day 7 you decide: if the headaches have fallen by half or more, keep the setup and you are done, and if they are much the same, go to step two, the eye test. Simple.
When an eye test is the fix
Three glasses problems produce headaches, and none of them can be fixed by breaks alone.
An uncorrected number
Mild long-sightedness (a plus number) is the classic hidden cause in young adults and children. You see perfectly well, because the eye’s own focusing muscle compensates all day, and by evening it aches. Mild astigmatism does the same. A small plus lens has ended years of afternoon headaches for people who swore their eyesight was fine.
An old number
Glasses more than 2 years old, or a number that has moved with age, pregnancy or diabetes. Pulling the glasses off to read is the giveaway.
Presbyopia after 40
From the early forties the lens stiffens and near focus fades, and the first sign is often not blur but headache after reading and a phone held further and further away. Reading glasses end it. Pride keeps it.
The test takes 20 minutes. Say when the headaches come. If you are under 40 and the plain test comes back “normal”, ask for the check with the drops that relax the focusing muscle (cycloplegic refraction), because a hidden plus number only shows up that way. Our eye test schedule by age says how often to repeat it.
See a doctor rather than an optician if the headache comes with double vision, a drooping eyelid, a new squint, halos around lights with a painful red eye, sudden loss of part of your vision, flashes and floaters, or eye pain on movement. Diabetes and high blood pressure both change the eyes, so if you have either, get the back of the eye examined as well as the number. Contact lens wearers with red, painful eyes must take the lenses out and be seen the same day. And any headache with the red flags listed above is not an eye strain headache, however many hours you spent on the laptop.
Dry eye: the strain you can feel
Blink less and the tear film dries, the surface blurs, and the focusing system hunts for a sharp image it cannot get, which produces the same headache plus stinging, grittiness, watering (a dry eye over-produces watery tears) and a blur that clears when you blink hard. Fans and AC aimed at the face make it worse. So do dust and contact lenses.
What helps: full-close blinks, the fan turned away from the face, a pharmacy lubricating drop used as the pack says, and a warm compress on closed eyes for 5 minutes at night if the lids feel crusty. Rosewater, cold splashes and rubbing do not.
A two-minute check for a hidden number
Sit at your normal screen distance and cover one eye with your palm. Is the text as sharp as with both eyes? Now the other eye. If one is clearly softer, or you have to squint, that eye has a number. Then look at a distant object across the room, then back at the screen. If the screen takes a second to sharpen, or aches to hold, your focusing is under strain. Neither test replaces the optometrist, but both make a good case for going.
Blue light glasses, screen filters and other things people buy
Blue-light-blocking glasses are sold as a headache fix, and they do not prevent eye strain, because the strain comes from focusing and blinking rather than from blue light. Anti-glare coatings do help a little with reflections. Night mode helps sleep and is harmless. It does nothing for a headache at 3 pm. Dark mode on a phone is comfortable for some people and worse for others (light text on black can be harder to focus), so use whichever lets you read at 40 cm without leaning in. The computer user eye care tips post has the rest of the setup, and the Eye Care series covers children, whose 20 cm phone distance strains their eyes more than two hours of TV across the room.
Rolling the eyes in circles does nothing for a glasses number. Palming, warm hands cupped over closed eyes for a minute, is a pleasant rest. Neither replaces the lens.
Eye strain headache: the questions people search
How do I know if my headache is from eye strain?
It sits across the forehead or behind both eyes, builds during screen or reading, goes with sleep, and comes with tired, dry or unfocused eyes. A one-sided throbbing headache with nausea, or one that wakes you, is something else.
Can wrong glasses cause headaches?
Yes, and so can no glasses when you need a small number. An old number, a hidden plus number or astigmatism, and presbyopia after 40 all show up as afternoon headaches before they show up as blur.
How long does an eye strain headache last?
An hour or two after stopping close work, and it is gone after a night’s sleep. A headache still there on waking is not eye strain.
Do blue light glasses help with headaches?
No. The strain comes from constant near focusing and reduced blinking, not from blue light. Breaks, distance, brightness and the right prescription help; a tint does not.
Does the 20-20-20 rule really work?
For the focusing part, yes: 20 seconds looking 6 metres away relaxes a muscle locked at near. It cannot fix a wrong glasses number, which is why the order is the week test, then the eye test.
Why do I get a headache after using my phone in bed?
Lying down, the phone sits 20 cm from the face, at full brightness in a dark room, with almost no blinking. Sit up, dim it, hold it further away, or stop 30 minutes before sleep.
Can dry eyes cause headaches?
Yes. A poor tear film blurs the surface, the eye works harder to focus, and the ache follows. Full blinks, a fan turned away and a lubricating drop are the fixes.
How often should I get my eyes tested if I work on a computer?
Every 2 years, sooner if headaches or blur appear, and every 1 to 2 years over 40. Anyone with diabetes or high BP needs the back of the eye checked yearly as well.
Can eye strain damage my eyes permanently?
No. It is tiring and it spoils your day, but it does not harm the eye or worsen a number.
Is a headache behind the eyes always eye strain?
No. Sinus pressure, migraine, tension headache and, rarely, raised eye pressure all sit there. If it does not follow the screen pattern or the week test changes nothing, see an optometrist or a doctor.