Can Your Windows Age Your Skin?

Using sunscreen during the summer when we spend much of the time outdoors is a given at this point, but what about when we are indoors? Or just running errands? After all, we can’t possibly suffer sun damage going between the house and car, can we? Should we be using a sun protective product on those occasions, too?

Many of us rely on the day’s UV index to decide whether we apply sunscreen or not. If it’s low (from 0 to 2), we often forego the protection, believing that we don’t need it. However, the daily UV index only measures the UVB rays, not UVA rays. UVA rays are prevalent year round, from dawn to dusk, and are the ones responsible for premature aging and some forms of skin cancer.

UVA rays are longer and able to penetrate deeper into the skin. Unlike UVB rays which give us that hot, warning sensation when we are in danger, UVA rays lack the same immediate intensity, lulling us into thinking that sunscreen is unnecessary on cloudy days. And unlike UVB, UVA rays can penetrate glass, exposing us to constant skin damage even when we are sitting by the window or driving in our cars.

The amount of UV rays that pass through windows depends very much on the type of glass. For example, the front windshield of a car is typically constructed of two layers of glass with a sheet of vinyl between which blocks almost 100% of all UV rays, both the ones that burn and age. Side and back windows, as well as the majority of those used in buildings, only block out the UVB rays. Unfortunately, unless the glass is specially treated, the UVA rays that cause wrinkles, dark spots and skin cancer can still get through.

I love sitting in front of the window in the sunshine as much as the next person, and there’s nothing more coveted at work than a corner office with windows. However, this also means we’re exposed 8 hours a day, 5 days a week, no matter the weather or season. And as UV damage is cumulative, sun exposure can result in significant damage over time.

Luckily, research has shown that it’s never too late to start being sun-smart. So before you give up your window seat or cancel this summer’s road trip, consider upping your use of sunscreen on a daily basis. For the face, not only can you get dedicated sunscreens for broad spectrum protection but many moisturizers, powders and makeup also contain sun filters for layering defence against UV exposure. Body lotions with sun filters are less common but are a great way of ensuring that you have some level of protection right out of the shower, even if they don’t eliminate the need for a “real” sunscreen.