Last updated on June 7th, 2017 at 07:13 pm
The UV Index established by the U.S. Epa (EPA) and the National Weather Service (NWS) has made many Americans more aware of the risks of sunburn and skin cancer from the sun’s ultraviolet (UV) radiation.
However did you know UV and other radiation from the sun also can damage your eyes?
Ultraviolet Eyeglasses: Is It Work?
Prolonged direct exposure to the sun’s UV rays has actually been linked to eye damage, including cataracts, macular degeneration, pingueculae, pterygia and photokeratitis that can cause temporary vision loss.
And brand-new research recommends the sun’s high-energy visible (HEV) radiation (also called “blue light“) might increase your long-term risk of macular degeneration. People with low blood plasma levels of vitamin C and other antioxidants particularly appear at risk of retinal damage from HEV radiation.
Threats Of Ultraviolet Radiation To Your Eyes
To protect your eyes from harmful solar radiation, sunglasses need to block 100 percent of UV rays as well as take in most HEV rays. Frames with a close-fitting wraparound style supply the best security because they restrict how much roaming sunlight reaches your eyes from above and beyond the periphery of your sunglass lenses.
While many people refer to ultraviolet radiation as UV light, the term technically is inaccurate since you can not see UV rays.
The 3 categories of invisible high-energy UV rays are:
UVC rays. These are the highest-energy UV rays and potentially could be the most harmful to your eyes and skin. Luckily, the atmosphere’s ozone layer obstructs essentially all UVC rays.
But this likewise means deficiency of the ozone layer possibly could allow high-energy UVC rays to reach the earth’s surface and cause severe UV-related illness. UVC rays have wavelengths of 100-280 nanometer (nm).
UVB rays. These have slightly longer wavelengths (280-315 nm) and lower energy than UVC rays. These rays are filtered partially by the ozone layer, but some still reach the earth’s surface area.
In low doses, UVB radiation stimulates the production of melanin (a skin pigment), causing the skin to darken, producing a suntan.
However in greater doses, UVB rays cause sunburn that increases the risk of skin cancer. UVB rays also cause skin discolorations, wrinkles and other signs of premature aging of the skin.
UVA rays. These are better to visible light rays and have lower energy than UVB and UVC rays. But UVA rays can go through the cornea and reach the lens and retina inside the eye.
Overexposure to UVA radiation has been linked to the advancement of particular types of cataracts, and research recommends UVA rays may contribute in advancement of macular degeneration.
Different eye issues have been connected with too much exposure to UV radiation.
As an example, UVB rays are thought to help cause pingueculae and pterygia. These growths on the eye’s surface can end up being unpleasant and cause corneal problems as well as distorted vision.
In high short-term doses, UVB rays also can cause photokeratitis, a painful inflammation of the cornea. “Snow blindness” is the common term for severe photokeratitis, which causes temporary vision loss normally long lasting 24-48 hours.
The risk for snow blindness is greatest at high elevations, however it can happen anywhere there is snow if you do not secure your eyes with UV-blocking sunglasses.
Since the cornea appears to take in 100 percent of UVB rays, this type of UV radiation is unlikely to cause cataracts and macular degeneration, which rather are linked to UVA exposure.
HEV Radiation Risks
As the name suggests, high-energy visible (HEV) radiation, or blue light, shows up. Although HEV rays have longer wavelengths (400-500 nm) and lower energy than UV rays, they permeate deeply into the eye and can cause retinal damage.
According to a European research study published in the October 2008 problem of Archives of Ophthalmology, HEV radiation — especially when combined with low blood plasma levels of vitamin C and other anti-oxidants — is associated with the advancement of macular degeneration.
Outside Risk Factors
Anyone who hangs out outdoors is at risk for eye problems from UV radiation. Threats of eye damage from UV and HEV direct exposure modification from day to day and depend upon a number of elements, including:
- Geographical area. UV levels are higher in tropical areas near the earth’s equator. The further you are from the equator, the smaller sized your risk.
- Altitude. UV levels are greater at higher altitudes.
- Time of day. UV and HEV levels are higher when the sun is high in the sky, normally from 10 a.m. to 2 p.m.
- Setting. UV and HEV levels are higher in broad open spaces, especially when extremely reflective surface areas exist, like snow and sand.
In reality, UV exposure can almost double when UV rays are reflected from the snow. UV direct exposure is less most likely in urban settings, where tall structures shade the streets.
- Medications. Particular medications, such as tetracycline, sulfa drugs, contraceptive pill, diuretics and tranquilizers, can increase your body’s sensitivity to UV and HEV radiation.
Surprisingly, cloud cover doesn’t affect UV levels substantially. Your risk of UV exposure can be quite high even on hazy or overcast days. This is because UV is invisible radiation, not visible light, and can penetrate clouds.
Determining Ultraviolet Rays
In the United States, the risk for UV exposure is measured using the UV Index.
Developed by the NWS and EPA, the UV Index anticipates each day’s ultraviolet radiation levels on a basic 1 to 11+ scale.
In addition to publishing the UV Index daily, the EPA also releases a UV Alert when the level of solar UV radiation that day is anticipated to be uncommonly high.
|UV Index||Risk Level||Recommendations|
|2 or less||Low||1. Wear sunglasses. |
2. If you burn easily, use sunscreen with an SPF* of 15+.
|3 – 5||Moderate||1. Wear sunglasses. |
2. Cover up and use sunscreen.
3. Stay in the shade near midday, when the sun is strongest.
|6 – 7||High||1. Wear a hat and sunglasses. |
2. Cover up and use sunscreen.
3. Reduce time in the sun between 10 a.m. and 4 p.m.
|8 – 10||Very high||1. Wear a hat and sunglasses. |
2. Cover up and use sunscreen.
3. Minimize sun exposure between 10 a.m. and 4 p.m.
|11+||Extreme||1. Wear a hat and sunglasses. |
2. Apply sunscreen (SPF 15+) liberally every two hours.
3. Try to avoid sun exposure between 10 a.m. and 4 p.m.
|*SPF = sun protection factor |
Information based on U.S. Environmental Protection Agency standards.
Kids Need UV Protection Even More Than Adults
The risk of damage to our eyes and skin from solar UV radiation is cumulative, meaning the risk continues to grow as we hang out in the sun throughout our lifetime.
With this in mind, it’s especially important for kids to secure their eyes from the sun. Children normally spend far more time outdoors than adults.
In truth, some specialists say that due to the fact that children have the tendency to invest significantly more time outdoors than a lot of adults, as much as half of an individual’s lifetime exposure to UV radiation can take place by age 18. (Other research pointed out by The Skin Cancer Foundation says slightly less than 25 percent of our life time exposure to UV radiation is sustained during youth.)
Likewise, children are more prone to retinal damage from UV rays because the lens inside a child’s eye is clearer than an adult lens, making it possible for more UV to permeate deep into the eye.
For that reason, ensure your kids’ eyes are safeguarded from the sun with excellent quality sunglasses. Also, motivate your child to use a hat on sunny days to even more reduce UV exposure.
Also read: Polarized Sunglasses
Sunglasses That Protect Your Eyes From UV And HEV Rays
To best safeguard your eyes from the sun’s harmful UV and HEV rays, constantly use great quality sunglasses when you are outdoors.
Search for sunglasses that obstruct 100 percent of UV rays which also soak up most HEV rays. Your optician can help you select the best sunglass lenses for your requirements.
To safeguard as much of the delicate skin around your eyes as possible, try at least one pair of sunglasses with large lenses or a close-fitting wraparound style.
Depending upon your outside lifestyle, you likewise might wish to explore performance sunglasses or sport sunglasses.
The amount of UV protection sunglasses supply is unrelated to the color and darkness of the lenses.
For instance, a light amber-colored lens can supply the very same UV security as a dark gray lens. Your optician can confirm that the lenses you choose offer 100 percent UV protection.
However for HEV security, color does matter. Many sunglass lenses that block a significant quantity of blue light will be bronze, copper or reddish-brown.
Again, your optician can help you pick the best “blue-blocking” lenses.
In addition to sunglasses, using a wide-brimmed hat on warm days can lower your eyes’ direct exposure to UV and HEV rays by approximately 50 percent.
More Tips About Sunglasses And UV Exposure
Lots of misunderstandings exist about the right sun defense for your eyes. Keep these tips in mind:
- Not all sunglasses obstruct 100 percent of UV rays. If you’re not sure about the level of UV protection your sunglasses offer, take them to your optometrist or optician for an examination. Numerous eye care specialists have instruments such as spectrophotometers that can measure the amount of noticeable light and UV radiation your lenses block. Practically all sunglasses obstruct a portion of HEV rays, however some tints obstruct more blue light than others. Blue-blocking sunglass lenses normally are bronze, copper or reddish-brown in color.
- Remember to use sunglasses even when you’re in the shade. Although shade lowers your UV and HEV exposure to some degree, your eyes still will be exposed to UV rays reflected from buildings, streets and other surface areas.
- Sunglasses are important especially in winter, because fresh snow can reflect 80 percent of UV rays, nearly doubling your total exposure to solar UV radiation. If you ski or snowboard, picking the right ski safety glasses is essential for sufficient UV defense on the slopes.
- Even if your contact lenses obstruct UV rays, you still require sunglasses. UV-blocking contacts protect just the part of your eye under the lens. UV rays still can damage your conjunctiva and other tissues not covered by the lens. Wearing sunglasses protects these delicate tissues and the skin around your eyes from UV damage.
- If you have dark skin and eyes, you still have to use sunglasses. Although your dark skin might offer you a lower risk of skin cancer from UV radiation, your risk of eye damage from UV and HEV rays is the exact same as that of someone with fair skin.
You need not fear the outdoors and bright days, as long as you are equipped with the right eye and skin protection to lower your UV exposure.