Your Neighborhood Optometrist

Monday, April 21, 2008

UV and You


We've all seen it lately, albeit not often enough and not for very long.

The sun is starting to shine and we're spending more time outdoors to soak it in. Along with the warmth and light comes UV radiation which we know can be harmful.

The wavelength for visible light ranges from 400nm to 700nm. The wavelength for UV radiation is shorter and therefore contains more energy which can cause molecular changes. You've probably heard of UVC (100nm to 280nm), UVB (280nm to 315nm) and UVA (315nm to 380nm). UVC for the most part, is filtered by the atmosphere. That leaves UVA and UVB to worry about.

UV damage of the eye can come in the form of photokeratitis (sunburn of the eye), pterygium (thickening of the tissue on the white of the eye), cataracts (clouding of the lens) and cancer of the lids and globe.

How you can minimize UV exposure:
  • Wear protective eyewear : make sure that both your tinted and untinted spectacles specifically protect against UV radiation. Some contact lenses now can block over 90% of UV rays. Make sure you are fit in the most protective materials available.
  • Wear a brimmed hat. This can block up to 50% more UV light.
  • Avoid mid-day sun when UV rays are strongest.
  • Take these precautions even if the sun isn't shining. Clouds don't block out UV.
Otherwise, have fun in the sun!