Sunglasses provide many benefits beyond fashion
This article was written by our team of UK HealthCare opticians.
Sunlight and ultraviolet (UV) exposure can lead to many eye conditions. Chronic exposure over days to weeks can cause permanent eye damage.
It’s believed this is due to what is called photo-oxidative damage, in which light reacts with the retina to produce molecules that are very reactive and cause damage to surrounding molecules. The sun's UV rays can damage your eyes even when the sky is overcast. There are several categories of UV rays with differing levels of energy: UVA, UVB and UVC.
- UVA: Lower-energy UVA rays, which are able to get past the cornea to the lens and retina, have been linked to the development of cataracts and macular degeneration.
- UVB: Any UVB rays that make it through the ozone layer are absorbed by the cornea, which can lead to photokeratitis, pingueculae and pterygia.
- UVC: While these rays have the potential to be the most damaging, nearly all are blocked by the ozone layer.
UV exposure can cause several other eye conditions. Keratitis — which is excessive exposure to harmful UV rays from the sun and/or tanning beds — can actually cause the cornea to burn (very similar to a sunburn).
Technically, your corneas suffer sun damage through a condition called photokeratitis. It’s also known as snow blindness, though you don’t have to be around snow to get it. Solar retinopathy is retinal damage that results from exposure to solar radiation. Patients with solar retinopathy tend to have a history of sun exposure, often from sunbathing.
The simplest way to protect against eye conditions caused by UV is to wear sunglasses. The sunglasses should have dark tint or be polarized. If you hold the glasses up to a light, the light coming through the lenses should appear grey, brown or yellowish brown. The light should not be blue, which is likely the most damaging light wavelength. Find sunglasses that offer the maximum UV protection, UV 400. UK HealthCare's Optical Shop shop can also make you custom sunglasses with UV protection and a solid tint or polarization.