Polarised and UV400 Are Two Different Things, and Only One Protects Him

UV400 is the safety specification, and it is the one that matters. It describes a lens that blocks ultraviolet light, which is what actually damages eyes over years. This is the claim to look for and the one to verify, because it is the reason to wear sunglasses at all rather than simply squint.

Polarisation is a comfort feature and has nothing to do with UV. A polarising filter cuts light reflected off flat surfaces — wet tarmac, a car bonnet, water — which removes glare rather than brightness. It is genuinely excellent for driving and near water, and it protects nothing.

Dark lenses without UV protection are actively worse than no sunglasses. Pupils open wider behind a dark lens, so an unprotected dark lens lets more ultraviolet into a wider pupil than bare eyes would. This is why the cheap unbranded pair on a market stall is not a harmless purchase, and why the rating is worth confirming.

• A brother who drives a lot, where glare is a daily problem
• Anyone who spends time near water, snow or wet roads
• Someone who loses sunglasses regularly and should not spend much
• A summer or holiday gift that will get immediate use

• Glare reduction is immediately noticeable while driving
• Aviator shapes suit a wide range of faces
• Cheap enough that losing them is not a disaster

The things worth checking before you order — this is where gifts like this most often go wrong.

• Polarised lenses can make some screens hard or impossible to read at certain angles — car dashboard displays, petrol pumps and phone screens are the usual culprits. It is not a fault and it surprises people who have never worn polarised lenses before.
• Aviators are a large shape and they suit a lot of faces but not all of them. On a narrow face they sit wide and slide down, and the fit at the bridge is what determines whether they stay on.
• Verify the UV rating is stated explicitly rather than implied by dark lenses. "UV400" or "100% UVA/UVB" is a claim; "tinted" and "shaded" are not.
• Metal-framed sunglasses at this price bend at the hinge before anything else fails. That is what you are trading away for the price, and it is a reasonable trade for something frequently lost.