Have you given much thought to your sunglasses? Specifically, do you know that just like your skin, your eyes are vulnerable to damage from either too much, or too little sun exposure? That’s why when you wear sunglasses, it’s critical you know how to choose the right ones.
This blog looks first at how the sun may be both damaging and beneficial to the eyes. Then we’ll consider how to choose the right sunglasses.
How May Excessive Sun Exposure Damage Your Eyes?
The skin around your eyes, including your eyelids, is among the thinnest and most sensitive on your body. This makes it particularly vulnerable to wrinkling and age spots from excessive exposure to ultraviolet (UV) rays. However, even your eyes themselves can be damaged by too much sun.
Experts such as Sumers and William Brown, O.D., Ph.D., of the department of ophthalmology at the Mayo Clinic (ref. 1), describe exactly what is likely to be happening to the naked eye when it's exposed to the sun:
- The white of your eye: Sun damage may cause the conjunctiva, the thin membrane covering the white of your eye, to thicken, become irritated, inflamed and grow over your cornea, interfering with your vision.
- Retina: If the macula, a part of your retina, deteriorates, it can lead to macular degeneration, a leading cause of blindness. There is some evidence of a link between macular degeneration and exposure to UV light (ref. 2).
- Iris: If you have blue eyes, you may be more susceptible to UV-induced eye damage, including macular degeneration.
- Lens: UV light may lead to the development of cataracts. This is a cloudiness on the lens of your eye which can interfere with vision.
- Cornea: Your cornea can become acutely sunburned, causing serious pain and temporary blindness. Chronic excessive exposure can lead to cataracts, especially if you have a poor diet with low antioxidants.
Also, please be aware that some medications can increase your eye's sensitivity to the sun. These include drugs such as birth control pills, diuretics, tranquilizers and tetracycline.
But too little exposure of the eyes to sunshine can also be damaging.
How Could Too Little Sun Exposure Damage Your Eyes?
On an average sunny day, your vision health may be impaired if you wear sunglasses. That is because you will block potentially beneficial wavelengths of light from reaching your eyes. You need the full spectrum of light wavelengths to nourish your eyes and enable them to function optimally.
Also, when full-spectrum light enters your eyes, it not only goes to your visual centres enabling you to see, it also goes to your brain's hypothalamus where it impacts your entire body.
For example, your hypothalamus controls body temperature, hunger and thirst, water balance and blood pressure. Additionally, it controls your body's master gland, the pituitary, which secretes many essential hormones, including those that influence your mood.
Your 'body clock' is also housed in tiny centres located in the hypothalamus, which is believed to control your body's circadian rhythm. This light-sensitive rhythm is dependent on Mother Nature, with its natural cycles of light and darkness, to function optimally. If anything disrupts these rhythms, like inadequate sunlight exposure to your body (including your eyes), there is a far-reaching impact on your body's ability to function.
This helps to explain how either too much or too little sunlight may impair your eyes.
But what if we find ourselves exposed to intense sun, like when skiing or boating? At these times, the snow/water greatly magnifies the sunlight, which could potentially cause the damage discussed above.
Then, sunglasses may indeed be necessary. Sunglasses are of course also very important when there is excessive glare, and especially when driving sunglasses can be an essential safety accessory.
So how do you choose the best ones? Sumers and William Brown, O.D., Ph.D, suggest useful tips for choosing sunglasses which are most likely to protect your eyes from sun damage.
Tips for Choosing the Best Sunglasses
Not all sunglasses are created equal. You can't use price as a gauge of quality as some of the higher priced brands may cost more because of fashion, not function. But this does not always apply.
CBS News (ref. 3) did a study comparing cheap sunglasses ($5 per pair) to high-end brands like Versace ($200 a pair). All 31 pairs carried claims that they offered excellent UV protection… and all but one (a cheap pair) actually did. In other words, if your sunglasses claim to offer good UV protection, they probably do.
If you're uncertain, take them in to an eye centre. Most will test the UV protection level of your sunglasses for free, and it takes less than 30 seconds to do so.
Other tips which may help you to choose wisely include:
- Avoid sunglasses that simply say "absorbs UV". Instead look for a label that says 99-100 % UV absorption or UV 400 (which means they block all UVA and UVB rays)
- Polarized lenses help cut glare allowing for crisper vision. However, this does not automatically mean that the lenses also protect against UV radiation from the sun. You can verify this by the label or the product seller. You are looking for evidence that the polarized lens are made of an impact-resistant material called polycarbonate, which contains UV protection.
- Darker lens colours don't necessarily mean better sun protection, as the UV protectant added to lenses is clear. Even gray, green, yellow or rose lenses can offer adequate UV protection
- Sunglasses made from pressed plastic will lead to distorted vision when you look to the right or left. Choose sunglasses with optically ground lenses for less distortion
- Larger frames and wraparound styles will shield more UV rays than smaller styles, as will close fitting glasses
- Beware of sunglasses called 'Eyeware', 'Sunware' or ‘Sun blockers’ which often have no UV protection.
So Do Sunglasses REALLY Protect Your Eyes?
Yes, if you choose wisely using the above tips, sunglasses can be very protective. This is especially when you are exposed for prolonged lengths of time to intense sun, and especially when near/on water or snow.
However, it’s also true that too much shading by sunglasses can be damaging. This is because you deprive yourself of the full spectrum of light wavelengths necessary to nourish your eyes and you hypothalamus, and enable them to function optimally.
What Is The Best Solution?
Perhaps the best solution is to use your body as your ‘Sunglasses Guide’? So if the light is uncomfortable to your eyes or causes you to squint, put on a hat, get in the shade or use sunglasses – temporarily only. In some cases you might find that a lightweight cap with a visor to protect the face and eyes from direct sunlight may be the best bet, as it still allows your eyes to benefit from the full spectrum of light.
Remember, too that a nutritionally dense diet loaded with various antioxidants like astaxanthin, lutein, zeaxantin and N-Acetyl Cysteine may help to improve your general eye health, and ability to protect the eyes from free radical damage. These valuable nutrients are also found in the Xtend-Life line of products.
Please visit this page (ref. 4) to see more natural ingredients which have supporting scientific evidence for eye health.
I live in the very hot, sunny Caribbean and rarely wear sunglasses unless I’m walking for long periods on the beach at noon. I rarely do that anyway as it’s just too hot….I burn my feet on the sand!
- Research by Sumers and William Brown, O.D., Ph.D., of the department of ophthalmology at the Mayo Clinic, described in the Huffington Post August 28, 2013 http://www.huffingtonpost.com/2013/08/28/how-to-buy-sunglasses_n_3826859.html
- A review: role of ultraviolet radiation in age-related macular degeneration. http://www.ncbi.nlm.nih.gov/pubmed/21646979
- Pricey Vs. Cheap Shades Put to the UV Test by CBS News http://www.cbsnews.com/news/pricey-vs-cheap-shades-put-to-the-uv-test/
- Some natural ingredients which have supporting scientific evidence for eye health. http://www.xtend-life.com/healthconditions/Eyes.aspx#NaturalTreatments