Sun exposure through glass is dangerous

Do you need to wear sunscreen indoors as well? We all know applying sunscreen before leaving the house, even if just to run errands or walking the dog is an absolute must to keep your skin safe from sun damage and the wrinkles it inevitably causes. But what about wearing sunscreen indoors?

If you never leave the house, or just pop in and out to get your daily bread, is it worth it to put sunscreen on – or are you just wasting away precious products? After all, sunscreen bottles are incredibly tiny for the amount of product you need to use every day, so if you can save a little, why not? And yet…. those pesky UV rays can get you even when you’re sitting near a window or driving a car. Well, some of them can… Here’s what dermatologists say about the need to wear sunscreen indoors:

Can You Get A Sunburn Indoors?

I’m old enough to remember the days when sunscreen was only for the beach. Back then, the consensus was that sunscreen served only to prevent sunburns. We didn’t yet know of the fast-raging powers of the sun and that being out on a warm day without protection would mean you’d get wrinkles and dark spots at an ever younger age. So if the sun wasn’t hot enough to burn your skin, you skipped the sunscreen. *sighs*

Is there any chance of the sun rays being so strong indoors? Even if you’re sitting all day in front of your big window office, can the sun rays get through and burn your skin? Yes and no. Let me explain. UV rays can most definitely get through windows. They’ve done research on drivers showing the side of the face next to the window develops wrinkles and dark spots and ages faster than the rest of your face. But they didn’t get a sunburn. How is this possible?

There are two types of UV rays. While all of them damage skin, UVA rays are mostly responsible for premature aging while UVB rays are mostly to blame for sunburns. Only UVA rays can get through windows, which is why you can get wrinkles but not sunburns indoors. But that doesn’t need you don’t need to wear sunscreen indoors.

Related: What’s The Difference Between UVA and UVB rays?

How effective is your sunscreen? Sign up to the newsletter below to receive the “Sunscreen Audit” Worksheet and find out if your sunscreen is really up to the job:

Do You Really Need To Wear Sunscreen Indoors?

So, if you can’t get a sunburn inside the house or office, do you really need to wear sunscreen indoors? The short answer is yes. “Glass windows filter out UVB rays [but] UVA rays can still penetrate through your windows, which is harmful to your skin,” explains board-certified cosmetic dermatologist Michele Green. The A in UVA is for aging. These rays are responsible for premature wrinkles and dark spots.

The worst part? They don’t even make your entire face age at the same rate! If you look at the face of someone who’s been driving cars or vans for a living for years, you’ll noticed that one side of his face – the side nearest to the car windows – has twice as many wrinkles and dark spots! The verdict is clear: you may think that not wearing sunscreen indoors is harmless, but all those unprotected sun exposure does add overtime – and it’s not pretty.

Want to know something even scarier? UVA rays also increase your risk of skin cancer. Don’t take any chances!

Can Sunscreen Protect You From Blue Light?

Blue light is the light emitted from screens, including laptop, phone, and TV. Not all sunscreen protect you from blue light. They must contain either or both zinc oxide or titanium dioxide to do the job well. According to a study published in the British Journal or Dermatology, “products containing microfine titanium dioxide are likely to offer superior photoprotection” against UV rays compared to other sunscreen formulations.

In case you’re wondering, zinc oxide and titanium dioxide are two mineral filters that provide broad spectrum protection against UV rays. Unlike chemical filters, they’re super gentle on the skin and don’t cause negative reactions even in people with sensitive skin. The catch? They have a greasy texture and can leave a white cast behind. Thankfully, brands are learning how to get rid of these unwanted side effects, so we can enjoy them without our faces turning into a white paste.

Do You Need To Reapply Sunscreen Indoors?

Now you know you need to wear sunscreen at home or in the office too. But do you need to reapply it often as well? You absolutely must… but not as often as you’d need to if you wear at the beach.

“UV rays creep into our rooms in ways we may not expect. Windows and doors do not filter out some UV rays and can cause damage to the skin,” explains Nava Greenfield, MD, dermatologist at Schweiger Dermatology Group. “Sunscreen is no longer effective after a certain period, usually around 80 to 120 minutes. If you are exposed to significant UV rays indoors, it would be wise to reapply.”

Part of the reason sunscreen loses its effectiveness is because sweating, swimming, and rubbing physically remove it from your skin. When you’re inside, that’s all less likely to happen, keeping your sunscreen on your skin – where it’s meant to be – for longer periods of time. But that doesn’t mean you can get away with not reapplying sunscreen at all. I recommend at least one reapplication mid-day. AT LEAST.

How Can You Prevent Sun Damage Indoors?

I’m not suggesting you stop sitting near windows or never get into a car again. Geez, where’s the fun in that? But, before you do it, you should take a couple of steps to protect yourself:

  1. Wear sunscreen: All day, every day, even when you’re staying indoors. Make sure it is broad spectrum. Not all sunscreen protect from UVA rays – and they’re the ones getting indoors! Click here to find out which UV filters protect from UVA rays. (P.S. You can’t go wrong with Zinc Oxide).
  2. Window tinting: Applying a protective UV film to your windows reduces UVA penetration by about 15-30%. I know that’s not always possible, especially in the office. But if it’s up to you, I highly recommend you consider it – especially for your car or if you live in a place where the sun is scorching hot for most of the year.

What Are The Best Sunscreens For Indoors?

The best sunscreen is the one you’ll use and wear repeatedly. Period. Having said that, some formulas are indeed better than others. First off, opt for a SPF of at least 30. Anything lower doesn’t provide adequate sun protection. “If you have a history of skin cancer, have melasma or hyperpigmentation, or tend to burn quickly, you should consider an SPF of 65 or more,” says Dr Green.

Mineral sunscreens also have the advantage here as they can protect you from blue light, a cause of concern indoors. Just make sure you pick a formula that’s not too greasy and won’t turn you into Caspar The Ghost. Here are a few of my fave picks:

  • Drunk Elephant Umbra Tinte Physical Daily Defense SPF 30 ($36.00): A tinted mineral sunscreen that protects you from all UV rays without leaving a white cast behind. Best suitable for dry skin. Available at BootsCult BeautySpaceNK, and Ulta.
  • Paula’s Choice Defense Essential Glow Moisturiser SPF30 ($26.40): Suitable for all skin types, this tinted mineral sunscreen provides broad spectrum protection, fights premature wrinkles, and dries to a luminous finish. Available at Cult BeautyPaula’s ChoiceSephoraSelfridges, and SpaceNK.
  • Supergoop! Mineral Mattescreen SPF 40 ($38.00): A mineral sunscreen that provides broad-spectrum protection and dries to a silky matte finish. It also minimises the look o pores. It’s best suitable for oily and combination skin. Available at Blue MercuryNordstromRevolve, and Ulta.

What If You Don’t Want To Wear Sunscreen Indoors?

I’m not your mum and you’re not a child. If you don’t want to wear sunscreen indoors, I can’t make you. But, I would encourage you to protect yourself by avoiding the sun as much as possible indoors too. How? Don’t spend time near big windows. If you must, draw the curtains. “If you simply stay out of sunlight penetrating your windows, no further indoor precautions are necessary,” says says Kenneth Howe, MD, a board-certified dermatologist at Wexler Dermatology. 

The Bottom Line

While we’re all on board (we are, aren’t we?) that we need to use sunscreen to protect our skin from UV damage outdoors, most people don’t realise you need to wear sunscreen indoors too. UVA rays can penetrate through windows and make you age way faster than you’d like to. Add blue light from all the screens we use on a regular basis and you’ve got a recipe for premature aging. Wear your sunscreen indoors too, ladies!