How to Choose Sunglasses | UV Protection First

Choosing sunglasses starts with 100% UVA/UVB protection, then fit, coverage, and lens tint for your specific activities.

Picking the right pair of sunglasses comes down to one rule that outranks every style consideration: block the UV rays. How to choose sunglasses well means treating UV protection as non-negotiable, then dialing in fit, coverage, and lens type for how you’ll actually wear them.

The Non-Negotiable: 100% UV Protection

Start by checking the label before you look at anything else. You want sunglasses marked “100% UV protection,” “100% UVA/UVB protection,” or “UV400.” The American Academy of Ophthalmology (AAO) is blunt about the standard: don’t settle for less than 100% UV protection.

Here’s the catch that surprises people: dark tint alone is not protection. A dark lens without UV filtering can actually be worse than no sunglasses at all, because the tint makes your pupils dilate while still letting UV radiation reach your eyes. Polarized lenses have the same blind spot — polarization cuts glare, but it’s not a substitute for UV filtering. You need both features in one lens.

Fit and Coverage: Where Most Pairs Fail

Good UV protection means nothing if light sneaks in around the edges. Frames should sit snugly on your nose and ears without pinching or slipping, and your eyelashes should never touch the lenses. Weight should distribute evenly between your nose and ears so the frame doesn’t dig in after an hour on the trail.

Coverage matters more than most shoppers realize. Larger lenses, wraparound styles, and frames that sit close to the face block peripheral exposure and side glare you’d otherwise get around standard lenses. If you’re buying for hiking, cycling, or any activity with lots of reflected light, wraparound coverage is worth the style trade-off. For readers ready to compare tested options for the trail, our roundup of the best backpacking sunglasses breaks down which frames hold up on multi-day trips.

Face shape gets a lot of attention in style guides, but fit and coverage matter more. Still, sizing cues help narrow choices online: check lens width, bridge width, and temple length on the spec sheet, and watch for descriptions like “fits smaller faces” or “fits medium to large faces.”

Lens Tint and VLT: Matching Lenses to Conditions

Visible light transmission (VLT) tells you how much light reaches your eyes, and REI’s guidance maps it to conditions. Dark sunglasses are unsuitable for low-light conditions, so keep a second pair if you’ll be out after sunset.

Tint color affects contrast and color perception, so it’s worth trying different tints outdoors to see which reduces glare best for your eyes. If you’re buying nonprescription lenses, run the AAO’s distortion test before committing: look through the lens at a rectangular pattern and move the glasses side to side. Wavy lines mean a bad lens — put it back.

One more compatibility note: contact lenses don’t replace sunglasses. The AAO notes that only some contacts carry UV protection, and even then, sunglasses remain necessary for full shielding. Prescription sunglasses and photochromic lenses add another layer of fit and optical considerations beyond basic UV labels.

Your Sunglasses Decision Checklist

Here’s the path to a solid pair, compressed:

• Verify the label: “100% UV protection,” “100% UVA/UVB,” or “UV400” — nothing less.
• Check coverage: frames close to the face, larger lenses, or wraparound styles for peripheral protection.
• Confirm fit: snug on nose and ears, no pinching, no slipping, lashes clear of the lenses.
• Test for distortion: the rectangle test catches bad nonprescription lenses.
• Match VLT to use: 0–19% for bright sun, 20–40% all-purpose, 40%+ for overcast, 80–90%+ for night.
• Keep polarized separate from UV: you want both, but they do different jobs.