The Ultraviolet (UV) Index has made Americans more familiar with the danger of sunburn, skin cancer and related conditions caused by UV radiation. This index was created by the National Weather Service (NWS) and the Environmental Protection Agency (EPA).
However, were you aware that the sun’s UV and high-energy visible (HEV) radiation may damage your eyes?
Prolonged exposure to UV rays has been associated with eye damage, which includes cataracts, pingueculae, macular degeneration, photokeratitis, and pterygia.
The risk from HEV rays
HEV radiation has less energy than UV radiation but they cause retinal damage when they penetrate the eyes. They typically have wavelengths of 400-500 nanometer (nm), making them longer than UV rays.
Recent research suggests HEV rays from the sun can increase the risk of macular degeneration. Individuals with low levels of vitamin C in their blood plasma are at higher risk of eye damage caused by HEV radiation.
UV rays are harmful to the eyes
To protect the eyes from destructive solar rays, wear sunglasses that absorb all UV rays and that block a high proportion of HEV rays. For best protection, wear close-fitting frames that wrap around the eyes. This minimizes the amount of stray sunlight that reaches the eyes from above, below and to the sides of the lenses.
There are three categories of UV rays:
UVC rays- Are the most energetic form of UV radiation and are potentially the most harmful to skin and eyes. Luckily for us, the earth’s ozone layer absorbs practically all of these rays.
However, this means ozone depletion could potentially allow UVC rays to travel all the way to the planet’s surface. Causing a higher incidence of harmful skin and eye problems. UVC radiation has wavelengths of around 100-280 nm.
UVB rays- Are less energetic than UVC rays but still have the potential to cause damage. These rays are partially blocked by the earth’s ozone layer. They have longer wavelengths of around 280-315 nm.
In lower doses, UVB rays facilitate melanin production in the skin. This makes skin darken, resulting in a suntan.
High doses of UVB radiation increases the likelihood of skin cancer. These rays also cause premature skin aging, skin discolorations, and wrinkles.
UVA rays- Have the lowest energy of all UV rays and are similar in wavelength and behavior to visible light. These rays enter the eyes and can reach internal eye structures such as the retina and lens.
Prolonged exposure to UVA rays can cause cataracts and there is some research that suggests they also cause macular degeneration.
Numerous eye issues are linked to prolonged exposure to UV rays.
For example, UVB radiation is believed to cause pterygia and pingueculae. These unsightly eye surface growths cause discomfort and distorted vision.
Snow blindness (photokeratitis) is another condition caused by UVB exposure. In this case, you’re exposed to a high dose of UVB radiation in a short amount of time. This temporary vision loss is due to corneal inflammation and can last 24-48 hours.
Snow blindness can happen anywhere snow is present but is most common in higher altitudes. Always wear UV and HEV rated sunglasses when out in the snow during daylight.
It’s important to wear sunglasses when you spend time outdoors during daylight. People who work outside or are in snowy conditions are at higher risk. Wearing sunscreen also will prevent sunburn, especially if you have lighter skin.
Dr. Joseph Cohen O.D.
Woodland Hills Optometrist
Receive an Excellent Service and Comprehensive Eye Care
Providing service in English and Farsi
19737 Ventura Blvd., Suite 201, Woodland Hills, CA 91364