From the moment we wake up until we fall asleep again our eyes are hard at work. Yet how many consider the damage the sun could do to their eyes during these daylight hours? Research shows that long term unprotected exposure to the sun’s UVA and UVB rays can lead to damage of the eye’s cornea, lens and retina which can affect the quality of vision.
These effects may take years to develop so it is important that the eyes are protected from an early age to reduce the onset of eye disease in later life. The amount of ultraviolet light reaching the earth has increased in recent years due to depletion in the ozone layer. Fortunately, in the UK the ozone layer is thinnest in spring when the sun is still quite low in the sky and there is plenty of cloud cover. However, eye protection is still important. People exposed to high levels of UV are thought to be 4x more likely to develop cataracts(clouding of the eye’s focussing lens).Studies have shown repeated UV exposure can contribute to the development of macular degeneration(the part of the retina responsible for detail central vision).
Acute(sudden) overexposure to UV such as at the beach or on the ski slopes (where more UV is around due to reflected radiation) can lead to a sunburn like condition of the cornea (the transparent membrane over the pupil area) called photokeratitis.
Other longer-term conditions include a growth on the cornea and conjunctiva(thin membrane covering the white of the eye) called pterygium, and also eyelid skin cancers.
Eye protection has taken on greater importance these days because more of us are living longer so our eyes are absorbing more UV rays than ever before. A 10-year delay in cataract onset could reduce the need for surgery by as much as half.
Children are at greatest risk from UV damage, especially the under 10-year-olds, since they have bigger pupils and clearer lenses which allow up to 70% more light and UV rays to reach the retina than in an adult’s eye. Kids also tend to spend more time outside without eye protection than adults do.
In Australia they are considering making sunglasses part of the school uniform.
The best way to protect eyes is to stop UV entering. Nowadays your everyday prescription spectacles can have a built-in UV filter (even some contact lenses have this).
- Various types of tints will also reduce glare and visible light.
- For example, category 3 tints are for general purpose sunglasses, a darker tint category 4 suitable for skiing, but not to be used for driving.
- Variable tints (photochromic) which darken with increasing UV light levels, can be useful since you don’t need a separate pair of glasses. These are less effective in the car unless the new xtractive transitions lens is chosen.
- Polarised tints reduce glare by filtering out horizontal UV waves (useful for driving & water sports).
- Anti-reflective coatings on spectacles also reduce lens surface induced glare.
- Wearing a wide brimmed hat or even baseball cap can also help with rays from above.
- Good sunglasses do not need to be expensive but always look for the CE mark, or the British Standard BSEN 1836:1997 to ensure they provide adequate UV protection - if they are not to this standard they may cause more damage than not wearing any sunglasses at all!
KINGSTON WHITE OPTICIANS stock a wide range of sunglasses (with or without your own prescription) for adults and children. Specific sports sunglasses are also available.
Please call in for free advice and further information sheets at: Kingston White Opticians, 2 Park Place, Knaresborough, HG5 0ER or telephone 01423 867550.