Why Sunglasses Are So Important For Your Vision And Eye Health

Article at a Glance: 

  • Getting natural sunlight is very important for regulating your circadian rhythms; however, like most things, you should aim to strike a healthy balance between sun exposure and protection.
  • Science shows that the sun’s UV rays can cause damage to your eyes. 
  • The two types of harmful rays are known as ultraviolet A (UVA) and ultraviolet B (UVB).
  • Sunglasses are a simple yet effective solution for blocking out harmful UV rays when exposed to natural sunlight outdoors.
  • TrueDark® sunglasses are unique in that they use transition lenses; these lenses block 99% of UV rays outdoors and 40-75% of artificial junk light while indoors.

Blinded by the Light may be a recognizable rock song recorded by Bruce Springsteen in 1973, but eye degeneration caused by UVA and UVB rays emitted by the sun is something to take seriously.

Sunlight that reaches us on the earth’s surface through the ozone layer is made up of two types of harmful rays: long wave ultraviolet A (UVA) and shortwave ultraviolet B (UVB). UVA rays penetrate deep into the dermis, the skin’s thickest layer. UVB rays will typically burn the top layers of your skin, yet both UVA/UVA are harmful to your eyes (retinal damage, including cataracts, and even wrinkles in the tender and thin skin around your eyes).

Yet we also know that some sunlight during the day is required for a healthy circadian rhythm. We suggest aiming to get 2-3 hours of sunlight in the morning hours when the sun’s rays aren’t quite as intense. If that still feels bright, or you don’t want the sun directly on your face, you can wear a hat while still getting the full benefit for your eyes.  After you have your daily dose of sunshine, you’ll want to avoid “too much of a good thing”. Start sporting some shades when you go outside.

Most sunglasses, whether they are a high-end online brand or a cost-effective pair at the corner store, will block out 99% or more of the UVA/UVB light spectrum. They tend to be a dark shade of brown or gray and polarized. Polarized, or anti-glare, glasses use a laminated filter that permits only vertical light rays to pass through and blocks nearly all horizontal rays to eliminate glare.  This is most noticeable when boating or fishing as you will be able to see through the surface when typically, you would just see the sun and sky reflected in the water’s surface.  Polarized lenses are best suited to reducing glare from water surfaces. Polarized lenses are permanently tinted dark and don’t change color.

The other type of sunglasses lens that is not readily available right off the shelf is a photochromic/transition lens. As opposed to polarized lenses, which can only be used outside due to their permanent dark tint, photochromic eyeglass lenses are clear when indoors. They then and darken automatically when exposed to UV irradiated sunlight. (Note: Photochromic lenses typically will not darken inside a vehicle as windshield glass blocks most UV rays.) Generally, transition lenses are used with a prescription for indoor use, transforming to sunglasses for outdoor use.

Here at TrueDark®, our customers wear glasses indoors to stop junk light during the day. And they go outside during the day. So we created an all-in-one solution for daytime eye protection. Introducing

TrueDark®  Daylights™ Transition Sunglasses that block  99% of both UVA and UVB light when you’re outside AND block 40% of blue light when you’re surrounded by junk light inside. Finally, daytime blue light blocking eyewear that can multitask (and now you can go outside and work)!

In addition to the clear blue blocking and UVA/UVB protection, these new TrueDark® glasses also have anti-reflective lenses. This is a great technology for sunglasses because it eliminates glare from a light source/sunlight reflecting into your eyes from the back surface of tinted/colored lenses when the sun is behind you.  AR coating reduces glare and “ghosting” images due to reflections at the lens surfaces. AR coating works both indoors and outdoors and can be found in conjunction with photochromic lenses on the TrueDark® Daylights™ Transition Sunglasses.


Sunglasses come in many shapes in sizes since they are accessories often used to exude style. But note that when it comes to eye health, functionality means so much more than style alone. Above all else, their main job is to help you protect your eyes from the sun’s harmful UVA/UVB rays. Some of the sun’s effects on the eyes include:

Cataracts – the clouding of the eye’s lens, resulting in blocked light and blurred vision. Studies have shown that prolonged exposure to UV light can increase the risk of having cataracts.

Macular degeneration – an eye disease in which the macula in the retina of your eye becomes damaged. The retina is nerve tissue found in the back of the eye that is responsible for sensing light. When it gets damaged, the result is vision loss.  Macular degeneration is the leading cause of irreversible blindness in the United States.

Pterygium (or Surfer’s Eye) –  a tissue growth that occurs over the white part of the eye, which can disrupt the cornea and cause astigmatism.

When purchasing sunglasses, be sure to look for ones that block out at least 99% of both UVA and UVB radiation so that you can keep your vision sharp and eyes healthy.  A wide-brimmed hat offers great protection, too!

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