Beyond Fashion, the Right Sunglasses Protect your Eyes

by Valerie Demetros

Aside from making you look cool, sunglasses also protect your eyes from harmful ultraviolet (UV) rays, reduce eyestrain in bright conditions and protect from other hazards.

Finding the right pair is important for your comfort and protection.

When purchasing sunglasses, you want to focus on Visible Light Transmission (VLT), style and tinting.

VLT is the amount of light that reaches your eyes through your lenses. It is measured as a percentage and is affected by the color and thickness of the lenses, material and coatings. Generally, look for 0% to 19% VLT for sunny conditions, 20% to 40% for all-purpose use, 40+% for overcast and low-light and 80% to 90% for night conditions.

For everyday use, casual style sunglasses can do a good job shading your eyes. They are not typically designed to handle much more.

On the other hand, sport sunglasses are designed specifically for activities like running, hiking, biking, etc. They are usually lightweight and fit for fast-paced action.

High-end frame and lens materials are more impact-resistant and flexible than casual sunglasses. Sport sunglasses also usually have grippy nose pads and temple ends to keep the frames in place and some have interchangeable lenses for different light conditions.

For skiing and hiking, you’ll need glacier glasses. These are designed to protect your eyes from the intense light at high altitudes and sunlight reflecting off snow. They often feature wrap-around extensions to block light from the sides.

In addition, polarized lenses will substantially reduce glare and work well if you enjoy water sports or are especially sensitive to glare.

But be careful, polarized lenses sometimes react with tints in windshields, creating blind spots and diminishing the visibility of LCD readouts. If this happens, consider mirrored lenses as a glare-reducing alternative.

You also can look for photochromic lenses, which automatically adjust to changing light intensities and conditions. These get darker on bright days and lighter when conditions darken.

As far as your lens color choices, these affect how much visible light reaches your eyes, how well you see other colors and how well you see contrasts.

Dark colors like brown, gray and green are perfect for everyday use and most outdoor activities. Darker shades are intended to cut through glare and reduce eyestrain. Gray and green lenses won’t distort colors, while brown lenses may.

Light colors (yellow/gold/amber/rose/vermillion) excel in moderate- to low-level light conditions and work for skiing and snowboarding. They provide depth perception and improve visibility of objects.

In the U.S., all sunglasses must meet Food and Drug Administration impact safety standards. And while no lens is 100% unbreakable, plastic lenses are less likely to shatter if hit directly. Most nonprescription sunglass lenses are made from some type of plastic.

For sports, polycarbonate plastic sunglasses are especially tough, but if they are uncoated, they do scratch easily so make sure they are coated.