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12 December 2011


Protect your eyes this December

LIFESTYLE NEWS - Planning to get a good tan at the beach this December? UV and other radiation from the sun don’t only damage your skin, but can also harm your eyes.

Extended exposure to the sun's UV rays has been linked to eye damage, including cataracts, macular degeneration, pingueculae and pterygia and photokeratitis that can cause temporary vision loss.

And new research suggests the sun's high-energy visible (HEV) radiation (also called "blue light") may increase your long-term risk of macular degeneration. People with low blood plasma levels of vitamin C and other antioxidants especially appear at risk of retinal damage from HEV radiation.

The three categories of invisible high-energy UV rays are:

UVC rays. These are the highest-energy UV rays and potentially could be the most harmful to your eyes and skin. Fortunately, the atmosphere's ozone layer blocks virtually all UVC rays. But this also means depletion of the ozone layer potentially could allow high-energy UVC rays to reach the earth's surface and cause serious UV-related health problems.

UVC rays have wavelengths of 100 to 280 nanometres (nm).

UVB rays. These have slightly longer wavelengths (280 to 315 nm) and lower energy than UVC rays. These rays are filtered partially by the ozone layer, but some still reach the earth's surface. In low doses, UVB radiation stimulates the production of melanin (a skin pigment), causing the skin to darken, creating a suntan. But in higher doses, UVB rays cause sunburn that increases the risk of skin cancer. UVB rays also cause skin discolorations, wrinkles and other signs of premature aging of the skin.

UVA rays. These are closer to visible light rays and have lower energy than UVB and UVC rays. But UVA rays can pass through the cornea and reach the lens and retina inside the eye. Overexposure to UVA radiation has been linked to the development of certain types of cataracts, and research suggests UVA rays may play a role in the development of macular degeneration.
To best protect your eyes from the sun's harmful UV and HEV rays, always wear good quality sunglasses when you are outdoors.

Look for sunglasses that block 100 percent of UV rays and that also absorb most HEV rays. Your optometrist can help you choose the best sunglass lenses for your needs. To protect as much of the delicate skin around your eyes as possible, try at least one pair of sunglasses with large lenses or a close-fitting wraparound style. Depending on your outdoor lifestyle, you also may want to explore performance sunglasses or sport sunglasses.

The amount of UV protection sunglasses provide is unrelated to the colour and darkness of the lenses. A light amber-coloured lens can provide the same UV protection as a dark gray lens. But for HEV protection, colour does matter. Most sunglass lenses that block a significant amount of blue light will be bronze, copper or reddish-brown.

In addition to sunglasses, wearing a wide-brimmed hat on sunny days can reduce your eyes' exposure to UV and HEV rays by up to 50 percent.

Remember to wear sunglasses even when you're in the shade. Although shade reduces your UV and HEV exposure to some degree, your eyes will still be exposed to UV rays reflected from buildings, roadways and other surfaces.
Even if your contact lenses block UV rays, you still need sunglasses. UV-blocking contacts shield only the part of your eye under the lens. UV rays still can damage your conjunctiva and other tissues not covered by the lens.

Frequently asked questions
Q: Who is at risk for eye damage?
A: Everyone is at risk. Every person in every ethnic group is susceptible to eye damage from UV radiation.

Q: When do I need to wear sunglasses?
A: Every day, even on cloudy days. Snow, water, sand, and pavements reflect UV rays, increasing the amount reaching your eyes and skin.

Q: What should I look for when choosing a pair of sunglasses?
A: No matter what sunglass styles or options you choose, you should insist that your sunglasses block 99 to 100 percent of both UVA and UVB radiation.

Q: Do I have to buy expensive sunglasses to ensure that I am being protected from UV radiation?
A: No. As long as the label says that the glasses provide 99 to 100 percent UVA and UVB protection, price should not be a deciding factor.

Q: Do all contact lenses block UV rays?
A: No. Not all contact lenses offer UV protection and not all provide similar absorption levels. Ask your optometrist for more information, and remember, a combination approach works best.

If you have any other eye related question or queries, contact Werner Fourie Optometrist on 044 873 4888.

- Mossel Bay Advertiser