Reviewed November 5, 2026

Your Hands Age in the Car: UV, Window Glass, and Driving

Laminated windshield glass blocks nearly all UVB and most UVA, but tempered side window glass blocks UVB while letting a large share of UVA through. The backs of the hands and the left arm sit in that UVA for every drive, which is why daily hand sunscreen or UPF driving gloves matter more than another face product for drivers.

Photoaging case photos love the truck driver, one side of the face aged decades past the other. The everyday version is quieter and sits on your steering wheel: hands that look older than the face they belong to, because the face got sunscreen and the hands got window light.

Car glass is not one material, and that is the point. The windshield in front of you and the side window beside you filter UV very differently.

Windshield versus side window

Windshields are laminated, two glass layers with a plastic interlayer, and that construction blocks essentially all UVB and the great majority of UVA. Side and rear windows are usually tempered single layer glass. Tempered glass stops UVB well but transmits a substantial share of UVA, the wavelength band tied to pigment and deeper photoaging.

A widely cited measurement of cars found side windows blocking on average about 71 percent of UVA, with wide variation by make and tint, against windshields at roughly 96 percent. Your left hand and forearm live next to the weaker pane for the whole commute, five days a week, for years.

What to do about hands specifically

The practical fix is unglamorous: keep a sunscreen tube in the car and coat the backs of the hands before driving, the same broad spectrum SPF 30 or higher you use on your face. The catch is durability. Hand washing, sanitizer, and steering friction strip it fast, so reapply after washing on days with more driving ahead.

UPF 50 driving gloves remove the reapplication problem entirely and are the honest recommendation for long commute drivers and anyone treating hand pigment or lentigines. They look odd. So does a ten year age gap between your hands and your face, and it lasts longer.

Tint is not a sunscreen claim

Aftermarket window films can raise side window UVA blocking substantially, and legal tint limits vary by state, so check yours before assuming a dark car is a protected one. Darkness alone is a poor proxy: a clear UV film can outblock a dark cosmetic tint on UVA specifically.

Do not let the car logic leak into the rest of the routine. Glass that blocks UVB means you will not burn on a drive, which removes the warning signal while UVA continues. No burn has never meant no exposure, in cars or anywhere else.

Frequently asked questions

Can I get sun damage through a car window?

Yes, mainly UVA through side windows. Windshields block most UV, but tempered side glass lets a large share of UVA pass, and UVA drives pigment and photoaging without causing a burn to warn you.

Do I need sunscreen for a short drive?

For a ten minute errand, the dose is small. The case for hand sunscreen builds with commute length and frequency, because daily half hour exposures accumulate across years. Long daily drivers get the clearest benefit.

Are driving gloves really UPF rated?

Many are, with UPF 50 ratings that block about 98 percent of UV. Look for a stated UPF rating rather than a generic sun glove. Gloves also survive hand washing, which is where hand sunscreen routines usually fail.

Does window tint block UV?

Quality films can block up to 99 percent of UV according to their specifications, but plain dark tint is not a guarantee of UVA protection. Ask for the film's UV rejection figure, and remember state law limits how dark front side windows can be.