Screen time and children's eyes: what parents should know
By See Better · Updated · 5 min read
The short answer
Screens do not permanently damage children's eyes, but long hours of close-up screen use are linked to short-sightedness, dry and tired eyes, and poorer sleep. Keep screen time within the limits for your child's age, build in breaks every 20 minutes, aim for two hours outdoors a day and switch screens off an hour before bed.
Key points
- The risk comes from long, close, unbroken viewing, not from the screen itself.
- The World Health Organization advises no screen time under age 2 and at most an hour a day from 2 to 4.
- Time outdoors is the best-proven protection against short-sightedness.
- Blue light glasses are not needed. Breaks and distance matter more.
How screens affect children's eyes
Short-sightedness
Spending a lot of time focused on anything close, whether a tablet, a phone or a book, is linked to children becoming short-sighted earlier and more quickly. Screens add to the risk mainly because they are held very close, for a long time, and often replace time outdoors. See short-sightedness in children.
Dry, tired eyes
Children blink far less when they stare at a screen. The surface of the eye dries out, causing stinging, redness, blur and rubbing. Focusing up close without a break also tires the eye muscles.
Sleep
Bright screens in the evening tell the brain it is still daytime and delay sleep. Exciting content does the same. Tired children then find it harder to concentrate the next day.
What screens do not do is cause permanent damage to the structure of the eye. There is no good evidence that the blue light from devices harms children's retinas.
Recommended screen time by age
These limits are based on World Health Organization guidance for young children and on general paediatric advice for older ones.
| Age | Recommended limit |
|---|---|
| Under 2 years | No screen time, apart from video calls with family |
| 2 to 4 years | No more than one hour a day. Less is better |
| 5 to 12 years | Agree clear limits on recreational screen time, with regular breaks |
| Teenagers | Balance screens with sleep, schoolwork, exercise and time outdoors |
For school-age children, the number of hours matters less than what screen time pushes out. If your child sleeps enough, plays outside every day and takes breaks, moderate screen use is unlikely to harm their eyes.
Signs of digital eye strain in children
- rubbing the eyes or blinking hard
- red or watery eyes
- complaining of headaches or tired eyes
- blurry vision after screen time
- holding the device closer and closer
- irritability when asked to read or concentrate
If these carry on even when screen time is reduced, have your child's eyes tested. An uncorrected prescription makes screen work much harder. Signs your child may need glasses has more to look out for.
Seven habits that protect children's eyes
- Follow the 20-20-20 rule. Every 20 minutes, look at something at least 6 metres away for 20 seconds. A timer helps younger children.
- Keep screens at a distance. Hold phones and tablets at least an elbow's length away, about 30 to 40 cm. A TV or monitor across the room is better than a phone near the face.
- Get outside for two hours a day. Daylight helps to protect against short-sightedness. Spread it across the day: before school, at break and in the afternoon.
- Stop screens an hour before bed, and keep devices out of the bedroom overnight.
- Sort out the lighting. Avoid using a bright screen in a dark room, and avoid glare from windows or lamps on the screen.
- Choose the bigger screen. For homework and videos, a laptop or TV at a distance is easier on the eyes than a phone.
- Set the example. Children copy what they see. Family meals and car trips without devices make limits easier to keep.
Do children need blue light glasses?
No. There is no good evidence that blue light glasses reduce eye strain or protect children's eyes. The habits above do far more. Read do blue light glasses really work? for the research.
Screens for schoolwork
Many South African learners now use tablets or laptops for school, and that time is not optional. Make it easier on the eyes: place the screen at arm's length with the top of the screen at or just below eye level, make the text larger, and insist on breaks. Balance schoolwork on screens with recreation away from them.
When to have your child's eyes tested
Test before Grade 1 and then every one to two years, and sooner if you see signs of strain or your child begins to sit closer to screens. See Better tests children's eyes at home across Gauteng for R450. When a child should have their first eye test sets out the schedule.
Frequently asked questions
Do screens damage children's eyes permanently?
There is no good evidence that screens cause permanent structural damage. The concerns are short-sightedness developing sooner, dry and tired eyes, and disrupted sleep, all of which are linked to long, close, unbroken screen use.
How far should a child hold a tablet from their eyes?
At least an elbow's length, roughly 30 to 40 cm, and further if possible. If your child always holds it much closer, have their eyes tested.
Is watching TV better than using a phone or tablet?
For the eyes, yes. A TV is viewed from further away, so the eyes focus less intensely. Sensible time limits still apply.
Can too much screen time cause a squint?
Ordinary screen use does not cause a squint. There have been reports of eyes turning inwards in children and teenagers who use phones for many hours a day at very close range. An eye that turns should always be examined, whatever the cause.
This article is general information and is not a diagnosis or a substitute for an eye examination. If you are worried about your eyes or your sight, see an optometrist or a doctor. Sudden loss of vision, eye injuries and severe eye pain are emergencies.
