With warmer weather approaching, it is important to visit the topic of UV exposure and the harmful effects that it could have on the eye. The sun’s primary danger is in the form of ultra-violet light or UV. Damage to the eye includes but is not limited to, cataracts, macular degeneration, benign or malignant growths and photokeratitis.
There are three types of invisible high energy UV rays. The first is UV-C, which is the highest energy and the most harmful but fortunately is fully absorbed by the ozone layer. Slightly lower energy is UV-B, which is only partially filtered by the ozone layer. This type of radiation causes sun spots, wrinkles and increases the risk of skin cancer. Relative to the eye, it can cause benign but cosmetically unpleasing growths called pingueculas and pterygiums or even cancer to the eye in the form of melanoma. UV-B has also been the culprit of UV photokeratitis, which is basically a sunburn of the cornea. This type of inflammation occurs mainly at high altitudes where UV exposure is greater. Skiers and mountain climbers are especially susceptible if not using proper eyewear. Because the cornea absorbs 100% of UV-B, it is unlikely to cause damages internally, only superficially. UV-A is the lowest form of energy that successfully passes through the cornea, putting the lens and retina at risk. Overexposure of this type of light can lead to cataracts and macular degeneration.
Another type of light that can damage the eye is high energy visible (HEV) radiation, also known as blue light. Blue light has been known to penetrate the eye deeply, causing retinal damage in the form of macular degeneration. Blue light not only comes from the sun but also from digital devices. Be aware that some offices are now using fluorescent light bulbs and LED lights that can also emit this type of harmful ray. Blue light protection glasses can help reduce the risk of future eye disease. Even if you do not wear glasses with a prescription, a nonprescription pair of blue light protection lenses is always recommended while using electronic devices.
Choosing the correct type of eye protection will reduce your risk of ocular damage. It is essential to have sunglasses that block near 100% of UV light. If you aren’t sure, bring your sunglasses to your nearest optometrist where the exact amount can be measured using a spectrophotometer. Wrap around style sunglasses are advised to keep the light from shining around the frames and into your eyes. Keep in mind that darker lenses or colored lenses do not necessarily provide more protection. In addition, polarized lenses only cut the glare, having no effect on UV at all. This type of lens is good for boaters or drivers to reduce glare off reflective surfaces like water and pavement.
The most crucial time to protect your eyes is during our early years of life. Sun damage is cumulative and if you start early and get in the habit of wearing sunglasses, your eyes will thank you in the future. Children tend to spend more time outdoors than adults. Some experts say nearly half of a person’s lifetime exposure to UV radiation occurs by the age of 18. Kids are also more susceptible to more retinal damage because the internal lens is less capable of blocking harmful light.
Keep in mind that clouds don’t affect the level of UV. You can still get sun damage during days that are overcast. The same goes for wearing sun protection under the shade. UV rays are known to reflect from buildings, roadways and other surfaces. Although certain contact lens manufacturers produce contacts that protect against UV, it is still important to wear sunglasses, as the contact lens does not cover the whole eyeball.
It is important to understand the key elements of how UV can damage the eye so that we can protect ourselves from any future damage. Just remember, sunglasses serve a purpose- they are not just a fashion accessory!