Do You Need Screen Indoors?

Newsflash: Even if you’re the type to avoid the sun at all costs, that doesn’t mean you’re off the hook when it comes to sunscreen.

But do you need sunscreen indoors?

You already know you need sunscreen when you’re spending time outdoors — the sun’s rays can damage skin in as little as 15 minutes.

Believe it or not, yes — sunscreen can protect your skin even when you’re inside. Here’s what you need to know:

When Do You Need Sunscreen Indoors?

There are two culprits when it comes to possible skin damage indoors: windows and electronic devices.

UVA rays from the sun can penetrate the windows of your home, making sunscreen essential even if you’re inside, says Joshua Zeichner, M.D., Director of Cosmetic and Clinical Research at Mount Sinai Hospital’s Department of Dermatology.

The exceptions: You don’t need to worry about ultraviolet rays if you’re in a windowless room, or if it’s nighttime.

It’s also important to consider your exposure to blue light from LED screens and how that may affect your skin.

“When you are indoors, you also are at risk for high energy visible light exposure,” Zeichner says.

HEV light, a.k.a. blue light, may be associated with signs of aging. Certain types of sunscreen will protect against blue light along with ultraviolet rays.

What Type of SPF Should I Use Indoors?

There are tons of different sunscreens on the market, and it can be tricky to figure out which is best.

When you’re looking for indoor SPF, Zeichner recommends sticking to SPF 30 and higher making sure the product is broad spectrum (meaning it protects against both UVA and UVB rays).

“I typically recommend using zinc-based sunscreens when you are indoors,” Zeichner says. “The zinc oxide gives UV protection and offers some level of protection against high-energy visible light as well.”

Follow the usual rules for application, Zeichner adds: Use a quarter-sized amount and apply it to your full face and any exposed skin.

Reapply every two hours.