For many of us, life is happening indoors — save for the occasional trip to the grocery store. And though it may seem trivial compared to the breaking news, keeping up with your skincare routine (with some adjustments) can have a big impact; in fact, a study found that repetitive routines may even alleviate stress and anxiety. That’s why we’re introducing our Glow Home series to offer solutions and tips for how to best care for skin while you’re safe at home.

It’s like an existential riddle for our times: If you put on sunscreen but didn’t actually go outside, then…did you really put on sunscreen? We managed to solve this one: Yes, you did, and good job — because you indeed still need sunscreen. “UV light, even through a window, can affect your skin,” says Debra Jaliman, MD, a dermatologist in New York City.

That’s because windows, and even indirect sun exposure through them, doesn’t do anything to mitigate the harmful effects of UV rays. In fact, “UV light can cause the same damage as if you would be on the beach or pool,” she says. “Every time the sun hits your skin, whether you are directly out in the sun or indoors getting indirect sun exposure, your skin is at risk of premature aging.” That leads to lines, wrinkles, and hyperpigmentation — and, of course, skin cancer is always a possibility.

Sure, if you’re hiding out in a bunker or keeping all the curtains drawn, then you could get by without the SPF 30 (which is the minimum amount recommended by the American Academy of Dermatology). But that’s not exactly realistic, nor is it a better option than just slathering on SPF.

There’s also the question of vitamin D, which is essential for bone health since “our body makes vitamin D when exposed to the sun,” says Jaliman. Sunscreen can limit the amount of vitamin D your skin absorbs — so you may need to take a supplement or incorporate more vitamin D-rich foods into your diet in order to get the daily recommended value. But either way, there’s no question about sunscreen: You need it, inside or outside.