Eye care guide
Sun and eye protection
Clinically reviewed · Last reviewed 2026-06-13
Why UV matters for eyes
The eye's lens and surface tissues absorb UV over decades. High lifetime exposure is linked to cataract formation, growths on the white of the eye such as pterygium, and skin cancers on the eyelids. UV also contributes to photokeratitis — sunburn of the cornea — from bright snow or water reflection.
Choosing sunglasses
Look for lenses that block UV or carry a UV 400 label. Dark tint alone does not guarantee protection.
- UV 400 or 100% UV protection labels
- Wraparound or large frames that reduce side light
- Polarised lenses for comfort on water or snow — still check UV protection
- Children need real UV-blocking sunglasses, not toy shades
Everyday habits
Peak UV is often mid-morning to mid-afternoon. Hats with a brim add valuable shade. Cloudy days still allow significant UV. Protect eyes during outdoor work, winter sports and holidays at altitude or near water.
WHO blindness prevention angle
Globally, cataract is the leading cause of avoidable blindness. While surgery treats cataracts effectively, reducing UV exposure across life is a low-cost prevention habit recommended in public health guidance alongside smoking avoidance and regular eye checks.
Frequently asked questions
Are cheap sunglasses safe?
They can be, if they genuinely block UV. Very dark lenses without UV filtering may let pupils dilate and allow more UV in, so check the label.
Do contact lenses replace sunglasses?
Some lenses offer UV filtering but they do not cover the whole eye or eyelids. Sunglasses and hats remain important.
Can the sun damage eyes on cloudy days?
Yes. Clouds reduce brightness but much UV still passes through. Habitual protection matters year-round in sunny climates.