We don’t always have the answers, but we have some people on speed dial who do — which is why we present to you our series FYI where we have experts explain if lip balm is actually bad, how often should you wash your hair and more.

Growing up, I constantly heard my mom reminding me to apply sunscreen before I walked out the door. She still reminds me to apply sunscreen when I’m sitting on the deck or lying on my beach towel outside. 

From my conversations with board-certified dermatologists, I know firsthand the importance of protecting my skin from the sun. I constantly make sure to include one into my skin care routine, but have always wondered if it’s necessary when all I’m doing is sitting at my desk or lounging around at home. That’s why I asked four dermatologists whether it’s important to wear sunscreen inside and other ways to protect your skin indoors.

SKIP AHEAD What is the difference between UVA, UVB and blue light? | Do you need to wear sunscreen indoors? | Do you need to wear sunscreen inside cars? | What type of sunscreen is better for indoor usage? | How much sunscreen do you need to apply when indoors? | What are other ways we can protect our skin from harmful light indoors?

Our top picks

What is the difference between UVA, UVB and blue light?

• UVA rays: UVA rays, a form of ultraviolet radiation, go deeper into the skin than UVB rays, primarily causing skin aging and long-term damage, including wrinkles and age spots, according to Dr. Danilo Del Campo, a board-certified dermatologist and founder of Chicago Skin Clinic. They do this because they break down collagen and elastic tissue, says Dr. Robyn Gmyrek, a board-certified dermatologist at Unionderm in New York City. UVA rays also play a role in the development of skin cancer. This type of radiation subtly harms the skin, initially leaving no noticeable marks but leading to serious damage as time goes on, says Del Campo. 
• UVB rays: Another variation of ultraviolet radiation, this type of ray targets the skin’s surface layer. They are mainly responsible for causing sunburn and significantly contribute to skin cancer risk. The intensity of UVB rays changes with the time of day and season, offering a somewhat predictable pattern yet remaining dangerously harmful, according to Del Campo.
• Blue light: Blue light, or high-energy visible (HEV) light, comes from the sun, digital screens, and LED lighting. Extended exposure to blue light has been linked to skin aging and hyperpigmentation. Recent studies suggest that blue light can induce oxidative stress in the skin, leading to premature aging. In our tech-driven world, this type of light is becoming an increasingly significant concern for skin health, he says.

Do you need to wear sunscreen indoors?

Yes. Even indoors, you should wear sunscreen, especially if you’re sitting by a window or using a digital screen for an extended period, according to Del Campo. And don’t think that a gloomy winter day or summer thunderstorms are reasons not to apply sunscreen indoors, says Gmyrek. 

It’s important for three different reasons. UVA rays and UVB rays can still pass through glass and expose your skin to its harmful rays, and the blue light that gets emitted through screens can also impact your skin’s health, he says

Do you need to wear sunscreen inside cars? 

“Just as a seatbelt is crucial for protection in your car, sunscreen is a safeguard for your skin, prepared for unforeseen exposure,” says Del Campo.

While car windows block out UVB rays, they generally do not stop UVA rays, which are responsible for skin aging and damage. Therefore, even inside a car, he says your skin is vulnerable to the harmful effects of sunlight. 

Applying sunscreen while driving or taking a road trip is a simple yet effective way to protect against UVA rays. It’s akin to invisible damage—you might not immediately feel the sun’s impact, but exposure can lead to skin issues over time without proper protection.

What type of sunscreen is better for indoor usage? 

Sunscreens come in three forms: mineral, chemical and hybrid, which is a combination of both. According to our experts, the choice depends on personal preference and skin type. Whichever option you choose, it should have an SPF rating of 30+ and offer broad-spectrum protection.

• Mineral: This type of sunscreen uses physical blockers, including iron oxide and titanium dioxide as active ingredients. These ingredients sit on top of the skin and create a physical barrier, blocking the ultraviolet and blue light from reaching the skin’s surface, according to Gmyrek. 
• Chemical: Chemical sunscreens use chemical filters as their active ingredients, which absorb into your skin, according to board-certified dermatologist Dr. Hadley King. Unlike creating a barrier, it will absorb UV radiation and convert it to heat that your skin releases. These also tend to be less visible on the skin, says Del Campo.

“Think of it like choosing between an umbrella and a raincoat — both protect you from rain, but the best choice depends on your needs. An umbrella (mineral sunscreen) might be more cumbersome but gives immediate, broad coverage. In contrast, a raincoat (chemical sunscreen) might be more convenient and comfortable but can take a little while to provide complete protection once put on,” says Del Campo.

Do you need to apply sunscreen to your face and body when indoors?

The answer is a combination of yes and no. According to board-certified dermatologist Dr. Mary Stevenson, it’s best to apply sunscreen to the areas most exposed, including your face, neck, chest and hands.

How much sunscreen do you need to apply when indoors?

Applying a nickel-sized dollop of sunscreen to the face and a generous amount to other exposed areas is essential. As a general guideline, about one shot glass full of sunscreen is recommended to cover the entire body if you’re spending time outdoors. Adjust the amount proportionately if you’re indoors but still exposed to sunlight through windows or near bright screens to ensure all exposed skin is adequately protected, says Del Campo.

What are other ways we can protect our skin from harmful light indoors?

If you don’t want to apply sunscreen at home or in the office, you can take simple measures like moving away from windows. But there are other options besides sunscreen, including installing window films or shades to intercept UVA rays, donning UV-protective clothing, and applying screen protectors on your digital devices to lessen blue light exposure, according to Del Campo. Think of it as building a comprehensive defense system against environmental elements, similar to how you would secure your home.

Meet our experts

At NBC Select, we work with experts with specialized knowledge and authority based on relevant training and/or experience. We also ensure all expert advice and recommendations are made independently and without undisclosed financial conflicts of interest.

• Dr. Hadley King is a board-certified dermatologist at her own private practice in New York City.
• Dr. Robyn Gmyrek is a board-certified dermatologist at UnionDerm Central Park in New York City.
• Dr. Danilo Del Campo is a board-certified dermatologist and founder of the Chicago Skin Clinic in Chicago, IL.
• Dr. Mary Stevenson is a board-certified dermatologist and associate professor at the Ronald O. Perelman Department of Dermatology at NYU Grossman School of Medicine.

Why trust NBC Select?

I am an NBC Select associate reporter covering skin care, hair care, gift guides and ongoing sales. I’ve also written articles about the best detangling sprays and clarifying shampoos. For this story, I interviewed four dermatologists and shared their recommendations.

Catch up on NBC Select’s in-depth coverage of personal finance, tech and tools, wellness and more, and follow us on Facebook, Instagram, Twitter and TikTok to stay up to date.