How do UV rays affect your eyes?
Warmer weather is finally coming, which means you can enjoy the sun more. You already know that you need to protect your skin by applying sunscreen with a high protection factor, but do not forget that your eyes also need protection. UV radiation, whether from natural sunlight or internal artificial rays, can damage the surface of the eyes, as well as the cornea and lenses. Unfortunately, however, many people are not aware of the dangers of UV rays. If you wear sunglasses that block UV rays, you can safely enjoy the summer, while reducing the risk of eye disease and eye-related conditions, whereas excessive exposure to UV light may increase the risk of eye disease. In this article, we will talk about how UV rays affect your eyes and some tips for how to protect your eyes from them.
What is UV radiation (i.e. UV index)?
UV (ultraviolet) radiation is part of the natural energy of the sun's rays1. In the electromagnetic spectrum, UV light has a shorter wavelength than visible light, making it invisible to our eyes. There are three types of UV rays2:
- UVA (ultraviolet A) – rays with longer wavelengths mainly associated with skin aging. They penetrate the skin deeper and penetrate clouds and windows.
- UVB (ultraviolet B) – rays with shorter wavelengths associated with burning of the skin. They act on the first, outer parts of the skin. The SPF (sun protection factor) label, which is written on most sunscreens, is actually a label that explains how long our skin is protected from UVB rays when exposed to the sun. UVB rays are easier to filter, and they do not penetrate windows.
- UVC (ultraviolet C) – rays with the shortest wavelengths absorbed by the ozone layer, and not the main cause of skin cancer.
In weather forecasts, we often come across the term UV index3. This is an standardized, international way of measuring and communicating the power (in terms of their potential to burn the skin) that UV rays have in a certain location at a certain time. The scale ranges from 1 to more than 11, and a higher value means more power.
Negative effects of UV rays on the eyes
Sunlight is the source of life and is necessary for the normal functioning of all organisms. However, if we are carelessly overexposed to sunlight, we can cause serious health problems. UV radiation has a negative impact not only on our skin but also on our eyes. We protect our skin by applying sunscreen, and we should likewise protect our eyes by wearing sunglasses.
During the summer, there is a particularly strong reflection of UV rays from the surface of the sea, sand, and gravel. At an altitude of 2000 meters or more, UV radiation is twice as strong as at sea level, so climbers, mountaineers, and people working in such environments are more exposed to these rays.
Short-term, intense exposure of the eyes to the sun can cause acute changes in the cornea, such as the so-called ultraviolet keratitis4 that occurs as a result of eye burns. This disorder presents with pain, burning, tingling, tearing, and redness of the eyes, with swelling of the eyelids and temporarily blurred vision. Long-term exposure to the sun can cause degenerative changes in the retina5 and consequent loss of vision. Changes in the conjunctiva in the form of bile ducts, "pinguecula or pterygium" (outer curtain), which can cause obstructions such as redness and irritation, and often distort the aesthetic appearance of the eye, are also common. The development of fogging of the lens is also accelerated (i.e. the appearance of cataracts6 in early middle age), and degeneration of the yellow dot (the point of the clearest vision) can occur on the retina, leading to damaged vision and snow blindness7. Even short-term exposure to direct sunlight without any protection can lead to the appearance of solar maculopathy (i.e. short-term or permanent damage to the yellow spot).
How to protect your eyes
The best thing you can do to provide your eyes with optimal protection is to wear sunglasses that will protect them from harmful UV rays. Some other tips are as follows:
- Wearing a hat can reduce direct exposure to the sun and glare. It is recommended to wear light-colored hats for both children and adults, especially during the strongest UV radiation between 10 a.m. and 4 p.m. The efficiency of such hats is only about 50%, because they do not protect you from reflected rays.
- Contact lenses with UV filters are recommended to be worn in combination with sunglasses. They do not provide UV protection to all parts of the eye and do not reduce the feeling of glare.
- Eye drops (artificial tears) moisten the eye and flush out impurities, helping to maintain a protective tear film, which otherwise shrinks due to high temperatures and wind. A poor tear film causes drying of the surface of the eyes, leading to redness, burning, and the urge to scratch. Eye drops can protect your eyes against artificial UV sources8.
How to choose the right sunglasses
The shape of your glasses should fit to the shape of your face. For the summer, we recommend models with larger lenses, rounded at the sides, to protect you from reflected rays. The glass material should be of high optical purity, lightweight, flexible, and scratch-resistant. It can be glass or plastic, and can also be made with diopters. Polycarbonate glasses are recommended, because they are more resistant to breaking. Photosensitive glasses change the intensity of the dimming depending on the intensity of the light and are suitable for driving. Mirror-effect glasses significantly limit the amount of light that enters the eye, making it easier to see. The color of the lens is usually gray, gray-blue, green, or brown, and is chosen according to purpose and taste.
Some of the sunglasses that offer optimal protection are MIRA sunglasses. Among the best polarized sunglasses are Aviator, Diva Black, Midnight, Sparkle, and Edge, and there are many more. All Mira sunglasses have tough frames to last a lifetime and polarized lenses that block 100% of the harmful UVA and UVB rays while providing clear, crisp vision. They are also very comfortable and fit everyone's needs. You can be fancy and modern at the same time, because these glasses are also trendy, and you can combine them with your favorite outfits. They are easy to clean and maintain, and come with their own microfiber carrying bag.
How do we know that sunglasses provide complete UV protection?
To choose appropriate, high-quality glasses that provide complete UV protection, it is best to consult opticians, pharmacies, or specialized sports stores. It is recommended to choose sunglasses that offer 100% or 99% protection from UVA and UVB radiation, and it is necessary to request a declaration in which the manufacturer states the characteristics of the eyeglasses and guarantees the quality of the product. The label “UV 400” indicates that rays with a wavelength shorter than 400 nanometers (all UVA and UVB rays) are blocked.
Should children wear sunglasses?
Children need sunglasses with 100% UV protection. They should get used to wearing them at an early age, because they spend much more time outside. You should not buy poor-quality glasses for children, plastic and dark, without a filter, because they may cause more negative effects and thus directly increase the harmful effects of the sun's rays.
Infants and very young children who cannot wear sunglasses should not be exposed to direct sunlight between 10 a.m. and 4 p.m. It is best to take them into the deep shade to protect them from reflective rays.You can choose from our best sunglasses for kids, including Kids-Rainbow,
To sum up
Eye protection is crucial for healthy vision. Age doesn’t matter, so you should start protecting your eyes from an early age. UV rays have some positive effects but can also negatively impact your eyes. That’s why wearing sunglasses with optimal protection and avoiding too much sun exposure are vital for protecting and improving your eyesight.
1. Gallagher RP, Lee TK, Bajdik CD, Borugian M. Ultraviolet radiation. Chronic Dis Can. 2010;29 Suppl 1:51-68. PMID: 21199599.
2. Guerra KC, Zafar N, Crane JS. Skin Cancer Prevention. 2021 Aug 14. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan–. PMID: 30137812.
3. Heckman, C. J., Liang, K., & Riley, M. (2019). Awareness, understanding, use, and impact of the UV index: A systematic review of over two decades of international research. Preventive medicine, 123, 71–83. https://doi.org/10.1016/j.ypmed.2019.03.004
4. Willmann G. Ultraviolet Keratitis: From the Pathophysiological Basis to Prevention and Clinical Management. High Alt Med Biol. 2015 Dec;16(4):277-82. doi: 10.1089/ham.2015.0109. PMID: 26680683.
5. van Kuijk F. J. (1991). Effects of ultraviolet light on the eye: role of protective glasses. Environmental health perspectives, 96, 177–184. https://doi.org/10.1289/ehp.9196177
6. Zigman S, Datiles M, Torczynski E. Sunlight and human cataracts. Invest Ophthalmol Vis Sci. 1979 May;18(5):462-7. PMID: 437948.
7. Taylor HR. The biological effects of UV-B on the eye. Photochem Photobiol. 1989 Oct;50(4):489-92. doi: 10.1111/j.1751-1097.1989.tb05553.x. PMID: 2687903.
8. Daxer A, Blumthaler M, Schreder J, Ettl A. Effectiveness of eye drops protective against ultraviolet radiation. Ophthalmic Res. 1998;30(5):286-90. doi: 10.1159/000055486. PMID: 9704331.