How to choose the right sunglasses | 5 min read

Sunglasses not only look fashionable; they also help protect your eyes from the harmful rays of the sun. Ultraviolet (UV) radiation from the sun can damage your skin as well as your eyes. Strong sunlight can burn the corneas and conjunctivas of your eyes. In addition, long-term exposure to UV radiation can contribute to eye disease, especially cataracts.

 You should choose sunglasses that

• reduce glare
• filter out 99-100% of UV rays
• protect your eyes
• are comfortable to wear
• do not distort colours

Step 1

Ultraviolet (UV) rays from the sun can damage your eyes by contributing to cataracts, macular degeneration and growths on the eye, including cancer. Ideally, sunglasses should block these two components of UV radiation at least by 99% and 95% respectively.

• UVB rays are the main concern for eyes. UVB radiation is considered more dangerous to eyes and skin than UVA radiation.
• UVA rays are the primary ones absorbed by your eyes. While they pose far less concern than UVB, doctors still recommend that they be avoided.
  
  

UV protection information should be printed on the hangtag or price sticker of any sunglasses you buy, no matter where you buy them. If it isn’t, find a different pair.

Step 2 

Look for sunglasses that filter out at least some blue light, as this can damage the retina and cause macular degeneration (vision loss from degeneration in parts of the eye). To make sure, try wearing them outside; a blue sky should appear gray with these on.

When choosing sunglasses, you have a wide array of options. Here are some tips on what to look for:

• Polarised lenses. Although polarised lenses protect against glare, they don’t meet the criteria for UV protection unless they contain additional UV-blocking material.
• Photochromic lenses automatically adjust to changing light intensities to protect you in a wider range of conditions. These lenses get darker (to block more light) on bright days, and lighter when conditions get darker. This type of lens protects the eyes from glare, sun and UV radiation while also maintaining visual acuity. Also, photochromic lenses do not distort colour.
• Polycarbonate lenses. A wise choice for children and athletes, as polycarbonate lenses shield the eyes from UV radiation and protect the eyes against impact injuries that may be sustained during play and sports.
  
  

Standard glasses can also be treated with a material that absorbs UV radiation sufficiently to protect the eye while retaining a clear, non-tinted appearance. In addition, UV protection can be obtained for most rigid contact lenses and many soft contact lenses.

Step 3

Choose a lens colour based on your preferences and comfort level. Gray doesn’t affect colour perception. Orange-brown lenses are a good choice for those with macular degeneration, since they filter out UV and blue light rays for maximum retinal protection. Green lenses distort colour less than other shades (such as red or yellow). Rose-coloured glasses really do make the world seem brighter. They provide excellent low-light visibility and enhance contrast. Mirrored coatings reduce glare by reflecting much of the light that hits the lens surface.

Step 4

The material used in your sunglass lenses will affect their clarity, weight, durability and cost. Choosing a frame is nearly as important as the lenses, since it also contributes to the comfort, durability and safety of your sunglasses.

Additional tips for protecting your eyes in the sun include:

• A darker lens does not necessarily indicate better protection, and lighter-tinted lenses offer better visibility. Check labels to find sunglasses that provide the best protection possible.
• For added eye protection, wear a wide-brimmed hat or cap. This keeps out sunlight from directly overhead.
• Never look directly at the sun — even through sunglasses — because doing so can cause permanent eye damage.

Fit tips

• Frames should fit snugly on your nose and ears, but not pinch or rub.
• The weight of sunglasses should be evenly distributed between your ears and nose. Frames should be light enough to avoid excess friction on these contact points.
• Your eyelashes should not contact the frame.

Sunglasses for children

Kids’ eyes are especially vulnerable to UV light, since they don’t have the same level of natural protection as adults.

Here are some helpful suggestions for choosing sunglasses for children:

• Check to make sure the sunglasses fit well and are not damaged.
• Choose sunglasses that fit your child’s lifestyle. The lenses should be impact resistant and should not pop out of the frames.
• Choose lenses that are large enough to shield the eyes from most angles. 

Are pricey glasses worth it?

A R100 pair of sunglasses can look pretty similar to a R2500 pair, so why pay more? The difference is in the technology, which offers more comfort, durability and performance. For around-town wear and while driving, an inexpensive casual pair may be all that you need. But for outdoor activities, especially high-impact ones such as cycling, performance glasses are usually well worth the investment.

MEDICAL DICTIONARY:

Ultraviolet rays (UV): invisible shortwave length radiation beyond the violet end of visible spectrum. Sunlight contains ultraviolet rays, which are responsible for the production of both suntan and – on overexposure – sunburn.

UVA: Ultraviolet rays with a longer wavelength – the closest to visible light. Mainly this is the ultraviolet light that reaches the earth, and which is responsible for sunburn as well as the forming of vitamin D.

UVB: Ultraviolet rays with intermediate wavelengths and especially responsible for cataracts and skin cancer.

Conjunctivas: the delicate mucous membrane that covers the front of the eye and lines the inside of the eyelids.

Cornea: the transparent circular part of the front of the eyeball. It refracts the light from entering the eye onto the lens.

Cataracts: any opacity in the lens of the eye hat results in blurred vision – it may be congenital or acquired.

Sources: Mayoclinic, Intelihealth