We are all aware of the importance of protecting our skin from the damaging effects of UV radiation. It is equally as important to look after our eyes as UV light is associated with a number of eye conditions such as pterygium, pingueculae, cataract and age related macular degeneration (AMD).
Although the ozone layer is depleted in the polar regions, the concentration of UV in the UK has remained pretty stable. However, there are certain times and conditions where the levels of UV radiation are higher:
- During the summer, general levels of UV are up to 3x higher than in the winter and damaging UVB may be up to 10x higher at this time of the year
- 70% of damaging UVB radiation is concentrated in the 3 hour band around midday
- Sand and water reflect UV radiation and increase the levels at the eye. The lack of landscape on the coast further increases risk.
- Snow and altitude combine to increase the reflection of UV significantly with a 30% increase in UVB at 2000m. The use of UV protection is essential when skiing.
- Some medications can increase the body's sensitivity to UV light
What to look for in sunglasses
All sunglasses that are sold in Europe must have a CE mark and conform to BS EN 1836:1997 ensuring standards of optical quality, robustness and UV protection.
There are 5 filter categories under the standard:
1. Clear / very light 80-100% light transmission
2. Light 43-80% light transmission
3. Medium 18-43% light transmission
4. Dark 8-18% light transmission
5. Very dark < 8% light transmission
These categories relate to the darkness of the tint and not the level of UV protection - a darker lens doesn’t always mean UV protection so look for sunglasses that block UVA and UVB rays. They should be marked as UV400.
Lenses in categories 4 and 5 are considered unsafe for driving.