09 Nov, 2018
Did you know that 60% of Aussies say that going blind is worse than having a heart attack or losing a limb? Yet 62% of us are still putting our sight at risk by not wearing sunglasses and a hat when in the sun?
Most people know that the sun’s rays are harmful to our skin. However, ultraviolet (UV) and other radiations are not only a major cause of skin cancer, they can also damage our eyes.
‘Sun cancer on the surface of the eye is a common problem that I see as a corneal specialist. These cancers often need both surgery and chemotherapy eye drops to save the patient’s sight.’ – says Dr Brendan Cronin, QEI Clinic’s Corneal and Anterior Segment Specialist.
But what is UV radiation?
Let’s take a closer look at UV radiation. It covers a range of wavelengths split into three groups that are invisible to the human eye and can’t be felt by the skin, but we need to be protected against it.
UVC rays are the highest energy UV rays and potentially the most harmful to our eyes and skin. The ozone layer should block all UVC rays – but this may change with ozone depletion, especially in Australia.
UVB rays have lower energy than UVC rays and are partially filtered by the ozone layer. However, some still reach the Earth’s surface so we need to be protected against them.
UVA rays are closer to visible light rays and have lower energy than UVB and UVC rays, but they pass through the cornea and reach the lens and retina inside the eye.
What are the dangers of overexposure to UV rays?
UVB radiation in low doses stimulates the production of melanin (a skin pigment), causing the skin to darken. In higher doses UVB rays can cause sunburn, skin discolouration, wrinkles and other signs of premature aging. UVB rays are also thought to help cause pingueculae and pterygia. These are growths on the eye’s surface and can become unsightly and cause corneal problems as well as distorted vision.
In high short-term doses, UVB rays can also cause photokeratitis, also known as snow blindness, which is a severe case of photokeratitis causing temporary vision loss.
UVA rays are linked to the development of cataracts and research suggests they may play a role in the development of macular degeneration.
Will I be affected?
Anyone who spends time outdoors is at risk for eye problems caused by UV radiation. 300 days of sunshine a year and eight to nine hours of sunshine a day put Queenslanders at high risk of overexposure to UV rays, so being sun smart is especially important in our community.
‘Remember, your skin may be tanned but the white of your eye isn’t! We should all wear sunglasses whenever we go outside. It is crucial that we install this important public health message into our children from a young age.’ – says Dr Cronin.
‘If your sunglasses are purchased from an optometrist, you can be assured that they meet the Australian Standards for UV protection. However, the same can’t be said for glasses sold at markets or bought online from overseas.’
How I can protect my eyes?
Choose sunnies with a high UV protection (category 2 and higher) and make sure they are close fitting and wrap around your eyes to reduce the reflected UV radiation and glare. Wearing a broad-brimmed hat when outside is a great way to increase the protection against UV rays. Exposure to UV is cumulative so it’s very important to protect children from an early age. When choosing sunnies for kids, check the label carefully – category 0 and 1 are not classified as sunglasses!