This woman's painful eyelid condition shows exactly why it's a bad idea to sleep in your makeup.

A 50-year-old woman in Australia developed a serious eye problem after wearing mascara for 25 years without removing it properly before going to sleep at night. Safia Fatimi / Getty Images / Via gettyimages.com Most people know you should remove your makeup before bed, but the occasional slip-up happens. And it can be especially tempting to pass out in a full face of makeup after an exhausting day at work or a late night out. But you may never fall asleep in your makeup again after seeing this photo of an Australian woman who suffered severe consequences from repeatedly sleeping in her mascara. The woman initially sought medical attention because she had the chronic sensation of having something stuck in both of her eyes. When doctors examined the woman, who admitted to "25 years of heavy mascara use with inadequate removal," they found that the mascara had accumulated in her eyelids. The woman was treated by Dr. Dana Robei in New South Wales, Australia, who wrote about the case in the May issue of Ophthalmology, the journal of the American Academy of Ophthalmology (AAO). Although this woman's case is rare, it is a reminder of why it's important to take care of your eyes and not let yourself get careless about makeup removal.

The mascara had formed tiny hard deposits that were embedded in the skin under her eyelids — some were coming out and scratching her eyeballs. American Academy of Ophthalmology / Via aaojournal.org

The underside of the woman's eyelids had multiple "darkly pigmented concretions," which means the mascara had accumulated into hard masses, like tiny rocks. "The concretions got embedded in the conjunctiva and it went deeper into the subconjunctiva layer, but you could still see it, sort of like a tattoo," said Dr. Rebecca Taylor, clinical spokesperson for the AAO and an ophthalmologist in Nashville. (Taylor didn't treat the patient.) The conjunctiva is the mucous membrane that covers the eye and the inside of the eyelids; it helps keep the eye moist and protects against infections, Taylor told BuzzFeed News. "She basically had these rough things stuck on the underside of her upper eyelid so every time she closed her eyes it would scratch her eyeball, particularly the cornea," Taylor said. The cornea is the thin, transparent layer of tissue on the surface of the eye that can cause a lot of pain and discomfort if scratched. The woman also had follicular conjunctivitis, or a reaction in the conjunctiva to the insult caused by the hardened mascara, Taylor said. If left untreated, the woman's corneal abrasions could have led to serious infection or vision problems.

Not removing makeup properly can cause a number of health problems in and around the eye. Lana Koster / Getty Images / Via gettyimages.com

Fortunately, this case was rare. But there are a number of common makeup mistakes that can cause pimples or rashes around the eye, viral infections, and sties — which are small bumps caused by infected follicles or glands on the eyelids. All of your makeup should come off before you go to sleep, especially anything sticking to your eyelashes. "Your eyelashes need to be clean because they are protecting the eyes ... they are nourished by oil glands and if those glands or the follicles are clogged, that can be a problem," Taylor said. When you apply your eye makeup, always use clean hands or applicators to avoid getting germs in your eyes. Also, try to avoid overcoating your lashes with mascara or caking concealer and powder over your tear ducts, which can cause irritation or dryness, said Taylor. In general, you shouldn't get any makeup in your actual eyes, especially if you wear contacts. Another big mistake is sharing eye makeup with friends or using samples at the cosmetic counters. It's an easy way to transmit pink eye and other bacterial and viral infections, said Taylor. You should also throw away eye makeup after three months because infection-causing bacteria can contaminate the products over time. Trust us, we tested makeup for bacteria and it was horrifying.

It's important to remove all of your eye makeup every night before you go to sleep using a gentle cleansing method. Fascinadora / Getty Images / Via gettyimages.com

There is no one ophthalmologist-approved eye makeup remover, but Taylor recommends anything that's hydrating, hypoallergenic, and free of fragrances and dyes. Try to avoid anything that's alcohol-based, because it can dry the eyes. You can purchase eye makeup removers or wipes, but there are also simple and cheap solutions. Taylor suggests using a cotton ball or pad with a petroleum- or oil-based product (Vaseline, Albolene, coconut oil) to get most of the makeup off. Then, rinse the remaining makeup and oil off with baby soap or a gentle cleanser. It's important to be gentle when removing makeup and to avoid harshly scrubbing the eyelids or skin around the eyes, which is very delicate. "The eyes are a gentle organ, so you have to use a very gentle touch," said Taylor.