The actress spent hours overnight at the hospital with photokeratitis after spending the day at a photo shoot—but the eye condition isn't something that just happens to celebrities. Here's everything you need to know to protect yourself.

Busy Philipps—actress, podcast host, and one of our favorite celebrity moms—posted on her Instagram Story on Monday that she thought she was having an allergic reaction. She couldn’t open her eyes. “It feels like there are shards of glass,” she told her followers.

After trying to go to bed, she ended up being in too much pain and went to the hospital. Early Tuesday morning, she told her Instagram followers that she was diagnosed with photokeratitis, essentially getting sunburn on her eyes from a photo shoot earlier that day. “It’s so on-brand though. I get one big magazine cover, and I do one photo shoot, and I burn my eyeballs,” Phillips said.

Though the incident was scary, it seems that after she discovered exactly what was happening, she was able to take proper remedies and made a quick recovery. By Thursday morning, she was already in a recording studio with singer Ben Lee creating tracks for his new musical.

We at Real Simple were curious to find out what photokeratitis exactly is, how we can protect ourselves from developing it, (and if it was only something that movie stars get!) We reached out to Natasha Herz, M.D., clinical spokesperson for the American Academy of Ophthalmology for the lowdown.

Real Simple: Can your eyes really get “sunburned?” Is photokeratitis essentially that?

Natasha Herz, M.D.: Photokeratitis can be compared to a sunburn, but instead of affecting the skin, it affects the corneas of the eyes. Exposure to ultraviolet (UV) rays can temporarily damage the cornea (the clear front part of the eye) and the conjunctiva (the mucous membrane that covers the front of the eye and lines the inside of the eyelids).

Symptoms include pain, redness, blurriness, tearing, a gritty feeling in your eyes, swelling, and/or sensitivity to bright light. You might have a headache or see “halos.” Other things to look out for include small pupils, eyelid twitching and, rarely, temporary vision loss. In rare cases, you may also experience temporary color changes in your vision. The longer you are exposed to UV rays, the more severe your symptoms will be.

RS: What situations might someone be at risk for developing photokeratitis?

NH: Sunlight is often the culprit when there is UV damage to the eye—such as if you stare directly at the sun. It can also be caused by sun reflection from sand, water, ice, or snow. Man-made sources of UV light that can also cause photokeratitis include tanning lamps, tanning beds, arc welding, or, as in Busy’s case, apparently, from the intensity and length of exposure to professional flood lamps during a celebrity photo shoot.

RS: Is this a common injury? Or is it only developed in people who are around camera flashes for sustained periods of time? Are there any conditions that might make you more prone to developing photokeratitis?

NH: It can happen anytime someone is exposed to a lot of bright sunlight, and particularly during a solar eclipse if you stare directly at it without wearing special glasses or using a special device. Note that viewing a solar eclipse without eye protection can also burn the retina, which can cause long-term blindness—unlike photokeratitis, which affects vision temporarily. Eye damage from UV rays is particularly common in the North and South Pole areas, or in high mountains where the air is thinner and provides less protection from UV rays. It’s called “snow blindness,” which is a form of photokeratitis that is caused by UV rays reflected off of ice and snow. And, it seems, being a celebrity also has its risks, because exposure to those large, bright professional lights can absolutely cause damage.

RS: Do sunglasses help prevent this? Is there something you should look for in sunglasses to protect against this?

NH: Yes, sunglasses can provide protection against photokeratitis. The good news is that sunglasses are very stylish, especially in Hollywood, right? Invest in sunglasses that block or absorb 99 percent or more of UV rays, or if you’ll be in the snow there are special snow goggles designed to block UV rays.

RS: How does one recover?

NH: Definitely go see an ophthalmologist if you can. Each situation will be different in terms of cause and severity. Symptoms usually go away gradually in a day or two. Photokeratitis can go away on its own, but just as your sunburn will feel better and heal quicker with lotion, your eyes will feel better and heal more quickly if you use lots of moisturizing drops. You should get preservative-free artificial tears and use them as often as every hour while awake. If you wear contact lenses, remove them immediately. Get out of the sun and into a dark room. A cold washcloth over your closed eyes will be soothing. You can also take over-the-counter, non-steroidal anti-inflammatory pain relievers. Since it is not an infection, you will not need an antibiotic; this can delay the healing of the ocular surface and is best avoided.

This interview has been edited for length and clarity.