Does looking at a phone for long hurt your eyes?

“Do not look at your phone so much, you will ruin your eyes.” You have probably said or heard this. The short and more accurate answer is: no permanent damage, but yes to tiredness.

Damage or tiredness?

According to the AAO, digital screens do not cause permanent eye damage, and sayings like “sitting close to the television ruins your eyes” are not true. Even so, discomfort after looking at a screen for a long time is real. It is called “digital eye strain”.

Its signs:

• Blurred vision
• Sore or tired eyes
• Dryness, burning or watering

It is similar to what you feel after hours of reading or sewing.

Why do the eyes get tired?

• Blinking less. The source says that while looking at a screen, blinking drops from about 15 times a minute to 5 to 7, and the eyes dry out.
• Light and glare. The brightness of the screen does not match the room, or light reflects off the screen.
• Distance and angle. The screen is too close or too high.
• Contact lenses. Wearing lenses for a long time makes dryness worse.

What helps?

According to the sources:

• Blink regularly and deliberately.
• Every so often look up from the screen at something far away.
• Keep about an arm’s length of distance, and place the screen a little below eye level.
• Match the screen brightness to the room and avoid reflections.
• Improve dry air with a humidifier.
• Use artificial tears when your eyes are dry.
• If you wear contact lenses, do not sleep in them and sometimes wear glasses instead.
• Get enough sleep.

Computer glasses, with a prescription suited to the middle distance, may help. These are different from “blue light blocking” glasses.

About children

Short-sightedness in children mostly starts between the ages of 6 and 13. The NHS source says its cause is not clearly known and does not say screens are the cause. But spending more time outdoors may prevent it getting worse. If your child holds screens very close or cannot see the board at school, have them examined.

When to be examined

If the signs do not improve with these measures, or:

• The eyes are often red, blurred or watery
• The eye is sensitive to light or painful

book an examination. If you have a sudden loss of vision, flashes of light or a dark curtain, do not wait, and see the guide “When should I get urgent help?”.