Your eyes and the sun

We are all aware that our skin can be damaged by UV radiation, but we rarely think much about our eyes and the sun. UV eye damage is cumulative, meaning it builds up over a lifetime and can have a permanent effect on our eyes and on our eye sight.

About UV Radiation

UV radiation, or ultra violet radiation, is comprised of 3 major wavelengths: UVA, UVB and UVC.

• UVA passes through the cornea to the lens and to the retina (the back of the eye).
• UVB is mostly absorbed by the cornea (the sensitive clear layer over the front of the eye).
• UVC radiation is mostly filtered by the earth’s atmosphere.

Australia has some of the highest UV radiation levels in the world. The UV index is an international standard measurement of the strength of UV radiation at a particular place and time, and is useful for knowing how harmful the sun at any given moment.  Unfortunately, it doesn’t reflect the amount of exposure your eyes get to UV. Cloudy days can be accompanied by significant UV because the radiation bounces off surfaces such as snow, water and sand.

UV light is not visible to our naked eye, so can be strong even when it doesn’t seem sunny or hot.

The level of the sun in the sky also effects your UV exposure: when the sun is low in the sky, UV radiation may affect your eyes more because your eyes and the sun are more directly aligned, so your eyes may actually suffer from more UV exposure in the early morning and late afternoon than from the midday sun.

Don’t be fooled into thinking that the heat you feel from the sun is similar to the amount of UV radiation you are getting. UV radiation can’t be felt.

Australia has high levels of UV radiation. This means we also see high levels of melanoma, which can occur in eyes as well as on our skin.

So protecting our eyes is important and serious. And the best way to do that is with sunglasses, on both sunny and overcast days.

Eye Conditions Caused or Aggravated by Sun Exposure

Short term conditions

Short intense exposure to UV can cause photokeratitis (sunburn of the cornea) and photoconjunctivitis (sunburn of the conjunctiva- the mucous membrane on the front or the white of your eye). Two well known forms of this are snow blindness and Welder’s flash.

Photokeratitis can be caused by looking at reflected UV from snow, water, sand, or bright surfaces.

Symptoms of photokeratitis are:

• sore, red, swollen, watery eyes
• gritty sensation with excess blinking
• photophobia (light sensitivity)
• blurred vision
• temporary visual loss
• perceived colour changes.

More serious and more permanent are retinal burns that are a more likely to occur when people are watching a solar eclipse.

Treatment includes:

• Avoiding rubbing eyes
• removing contacts, makeup and false eyelashes
• cold compresses,
• a darkened room
• using lubricant eye drops
• oral painkillers
• avoiding contact with chlorinated water and sea water

Long term conditions

Cataracts

Cataracts are a clouding of the lens of the eye which occurs most commonly in those over 60.

Sun exposure with speed up cataract formation. Vision may seem hazy, clouded, blurry or smudgey. Halos may appear and colours don’t look as bright.

If the cataract is advanced it may be visible to those around you as a white film in the pupil.

Pterigium / Pingueculae (“surfer’s eye”)

These are soft, fleshy overgrowths on the surface of your eye. They form in the corner of the eye near your nose and grow towards the cornea, sometimes encroaching on it and effecting vision. They are more often seen in the people who spend long periods outdoors, exposed to UV or people who work in dusty environments. They are painless and they are benign, however, they may cause problems for contact lens wearers and occasionally will need to be surgically removed.

Skin cancers

Skin cancers of the eye lids are common in Australia, with over 50% of those over 60 being diagnosed with a skin cancer around their eye.

Ocular melanoma can also develop, which is the most serious of eye-related skin cancers. Regular eye checks, as well as skin checks, are the best way to catch cancers early and improve the success of treatment.

Macular Degeneration

Macular degeneration is caused by deterioration of the retina and can cause visual distortion or loss.

It leads to progressive loss of central vision.

UVA is responsible for more of the damage to the macula, which is the central area of your retina.

The Amsler grid is a common test for macular degeneration and involves a chequerboard pattern of straight lines in which the lines appear to be wavy or missing when the condition is present.

Clearly, your eyes and the sun don’t always play well together. Protecting your eyes with UV protecting sunglasses is paramount to ensuring eye health.