Health
UV and Your Eyes: Cataracts, Pterygium, and the Sunglasses You Actually Need
UV damage to eyes accumulates silently for decades. The evidence linking UV to cataracts, macular degeneration, and how to pick real UV-blocking sunglasses.
The World Health Organization estimates that 20 percent of cataracts globally are caused or worsened by UV exposure. Unlike skin, the eye has no visible warning — damage compounds silently over decades until vision starts to fail.
How UV damages the eye
UVB is absorbed by the cornea and lens. Chronic exposure accelerates cataract formation (clouding of the lens), causes pterygium (a growth of tissue over the cornea), and contributes to macular degeneration. Acute high-dose UV — snow reflection, welding without protection — produces photokeratitis, the painful 'sunburn' of the cornea.
What to look for on sunglass labels
- UV400 — blocks 99 to 100 percent of UVA and UVB
- 'Blocks 100 percent UV' or 'meets ANSI Z80.3'
- Category 3 lenses for bright conditions, Category 4 for glaciers or open water
- Wraparound frames — block reflected UV from below and the sides
Kids need UV sunglasses too
Children's lenses are more transparent to UV than adult lenses, so more UV reaches the retina. The American Academy of Ophthalmology recommends UV-blocking sunglasses from infancy for bright outdoor exposure.
Key takeaways
- UV drives cataracts, pterygium, and macular degeneration.
- UV400 or 'blocks 100 percent UV' is the label to check.
- Kids need UV sunglasses; their lenses transmit more UV.