Do You Need Sunscreen Indoors? UVA Through Windows, Explained
If you sit by a window or commute by car, the glass blocking your sunburn isn't blocking the rays that age your skin - here's the fix.
Ordinary window glass filters most UVB but lets aging-and-cancer-linked UVA rays through. UV window film can block more than 99% of UVA and UVB.
Skin-cancer experts point out that everyday, incidental exposure - sitting near a window or driving - adds up over years, and that UVA is the wavelength most associated with photoaging because standard glass does little to stop it.
Questions we get a lot
Does window glass block UV rays?
Ordinary glass blocks most UVB, which is the main cause of sunburn, but it lets much of the UVA spectrum through. UVA is linked to skin aging and skin cancer, so glass alone is not full protection. UV window film can block more than 99% of both UVA and UVB.
Do I need sunscreen if I work indoors near a window?
If you sit near a window for long stretches, daily sunscreen is a reasonable precaution against UVA that passes through glass. UV window film is another option that can cut more than 99% of UVA and UVB. Incidental exposure like this is one of the sneaky ways people accumulate sun damage.
Should I wear sunscreen while driving?
Side and rear car windows often let UVA through, so the arm and side of the face nearest the window can accumulate exposure on long drives. Daily sunscreen or UV-blocking window film helps. The Skin Cancer Foundation lists driving among the overlooked sources of UV exposure.
r/SkincareAddiction: 'My desk is right next to a huge window - am I really getting sun damage indoors?'