All natural 5 October, 2018 Maria Clara Restrepo E.
Sunglasses are an essential accessory to protecting your vision from the harmful effects of the sun. They should not be chosen for aesthetic reasons, however.
The incorrect use of sunglasses can lead to eye problems such as keratitis, cataracts or macular degeneration. The Catalan Retina Institute in Barcelona, Spain, offers a few tips to keep in mind when purchasing them.
Check for their scale of protection:
- 0: Lets between 81% and 100% of the light in. These types of sunglasses are aesthetic and are only recommended for completely cloudy days or indoors.
- 1: Allows for between 44% and 80% of light to pass. These sunglasses can be used when the sun’s rays are not intense.
- 2: Allows for between 19% and 43% of light to pass. Recommended when the sun’s intensity is moderate.
- 3: These lenses filter between 8% and 18% of light. They can be used when the sun’s rays are intense, especially on the beach or in the mountains.
- 4: Allows for between 4% and 7% of light to enter. Use when the sun is extremely intense.
These categories are often confused with the level of protection sunglasses provide against ultraviolet rays, which are divided into three types of rays:
- UVC Rays: Absorbed by the ozone layer.
- UVB Rays: These are medium-range rays and are what cause sunburns after prolonged exposure to the sun.
- UVA Rays: These are long-range rays and have the ability to pass through the cornea and reach the retina. They are also what cause cataracts.
Before purchasing a pair of sunglasses, talk with an ophthalmologist about what kind of UV ray protection they offer and what lenses are right for you according to your vision.
Keep in mind
- Dark lenses are commonly mistaken for providing more protection than lighter lenses. What is most important, is that the sunglasses to provide UV protection.
- If you buy sunglasses without any UV protection, the pupil dilates to take in more light and to see better, which is when ultraviolet rays (UVC, UVB and UVA) can pass directly through to all areas of the eye (pupil, lens, retina).
Related article: Prescription sunglass to protect your eyes (article in Spanish)