Sunglasses, decoded: lens, frame, and fit

Sunglasses are sold on shape and bought on feel, and most of the buying advice is about the wrong two things. The lens does three separate jobs — blocking UV, cutting visible light, and killing glare — and a frame’s job is to hold the lens in front of your eyes at the right distance. Decode those and the category stops being a guessing game.

The lens does three jobs

UV blocking is the health part, and it’s invisible: you can’t see it, feel it, or judge it by how dark the tint looks. A dark lens without a UV treatment still passes UV. What you can verify is the claim — “100% UV” or “UV400” on the label or the product page.

Visible-light reduction is the tint’s job, and it’s measured in how much light the lens absorbs. Ray-Ban’s product pages state that the classic G-15 green lens “absorbs 85% of visible light” and blocks most blue light — a mid-depth tint that keeps colors natural. Gradient tints are dark at the top and clear at the bottom; mirror finishes cut brightness further but add scratch sensitivity.

Glare control is the polarized job, and it’s the one people misunderstand. Polarization filters the horizontally oriented light that bounces off flat reflective surfaces — water, wet road, snow, car hoods. Ray-Ban states its polarized lenses “block more than 99% of the reflected light.” What polarized does not do: add UV protection, or reduce overall brightness beyond what the tint already does.

Frame shape vs face shape

The face-shape rules (round faces take angular frames, square faces take round ones) are a starting point, not physics. Two measurements decide fit more reliably.

Frame width vs face width. The frame should end about where your face does at the temples. Spill past that and the temples splay; fall short and the frame floats.

Bridge fit. The frame should sit on the bridge of your nose, carried by the bridge or the nose pads — not clamp at the sides, not slide down when you smile.

Lens height is the third dial: taller lenses cut more side glare; shorter ones read lighter on the face.

Nose pads and clamping

This is where cheap sunglasses betray themselves. On metal frames, adjustable nose pads let you set where the frame sits — the Aviator’s wire frame carries them, which is a large part of why it fits so many faces. On acetate frames, the nose pads are molded into the frame and fixed; a bridge that’s too narrow pinches, too wide slides.

Temples matter too. They should follow your head’s contour and hold without pressure at the points above your ears. If you can feel the frame at three separate pressure points, the fit is wrong no matter how good the shape looks in the mirror.

What polarized actually solves

Polarized earns its upcharge in specific scenes: driving into low sun on a wet road, water, snow, and any scene with large flat reflective surfaces. In those conditions it cuts the glare that makes you squint, and the reported difference is immediate. For urban walking and general wear, it’s a smaller upgrade than the marketing suggests.

Two honest caveats from the pattern of user reports: polarized lenses can make some LCD and dashboard displays look odd, and they don’t touch the diffuse glare of an overcast sky.

What we’d pick

Three frames that split the job by material and shape:

• Ray-Ban Original Wayfarer Classic — the acetate default that fits nearly every face.
• Ray-Ban Aviator Classic — the metal teardrop with adjustable nose pads, in polarized.
• Ray-Ban Clubmaster Classic — the browline hybrid, also polarized.

The picks below break down what each frame does and when it earns its keep. Prices and availability move — check the live listing before buying.