June 12 2002
Wearing sunglasses is not just about looking cool when it's hot. They also protect the eyes against the sun's harmful UV rays. Exposure to the sun's UV radiation can lead to a sunburn-like condition called photokeratitis, which is normally a temporary, but uncomfortable, condition.
Long-term exposure to the sun's harmful invisible rays can speed up ageing of the macula, the focusing part of the retina, and can also lead to cataracts. So, how can you tell if sunglasses will do their most important job of all and protect the eyes?
The British Standards Institution tests sunglasses to BS EN 1836:1997, and has got together with the UK Eyecare Trust to produce this checklist:
Top Tips for Buying the Best Sunglasses
Expensive sometimes means better, but not in the case of sunglasses. What really counts is the degree to which the lenses filter out harmful UV rays. Look out for glasses carrying the "CE" Mark and British Standard BS EN 1836:1997, which ensures that the sunglasses offer a safe level of UV protection.
Sunglasses for Driving
When buying sunglasses which will be worn for driving, make sure they are in the filter category range of 0-3. A lens carrying a filter category of 4 will be too dark for safe driving.
Unless the glasses carry the British Standard BS EN 1836:1997, do not confuse the shade of the lenses with their ability to filter UV rays. Dark sunglasses may still allow UV rays to enter the eye and can be MORE harmful than wearing no glasses at all, because they cause the pupil of the eye to dilate therefore allowing more UV rays to enter. Therefore, when buying sunglasses with very dark lenses it is more important than ever to ensure they offer good UV protection. Sunglasses are marked with a filter category number from 0-4, where 4 is the darkest lens. 4 offers more comfort in bright sunlight as it avoids straining the eyes.
Filtering Blue Light
Ideally sunglasses will also absorb high energy visible radiation, known as blue light. This will enable the glasses to be worn for extended periods without tiring the eyes. It is recommended that no more than 95% of blue light should be filtered to avoid colour distortion.
Scratched lenses will scatter the suns light and could cause glare around the area of the scratch. Look after sunglasses by keeping them in a case and cleaning them with a mild detergent and water or a special lens cleaner.
Contact Lenses with Protection
Contact lens wearers can now also enjoy the added protection of in-built UV protection. Contact lens practitioners will have details of all the latest products available.
If you already wear spectacles you can have sunglasses made to your prescription
Finally, have some fun with sunglasses. Designs are getting more flamboyant and adventurous, so make the most of the wide range available and add a real twist to summer dressing but make sure that the lenses are big enough to protect the eyes from stray light. Sunglasses may be vital for protecting the eyes, but that does not mean they can not look stylish and individual.
CONTACT BSI PRESS OFFICE:
Wilma Tulloch on +44 (0)20 8996 6330 OR
Marc Edney on +44 (0)20 8996 6330