Quit these habits for the sake of your eyes.

Pretend for a minute that using your contact lenses is like a game of football. (Just roll with it.) Your contacts would naturally take the starring role of quarterback. Your contact lens case, on the other hand, would be more like the water person: a crucial part of the whole operation that sometimes gets unfairly overlooked.

Proper use of everything related to your contact lenses—including the case—is essential for good eye health. Using contact lenses already puts you at an increased risk of issues such as dry eye, according to the Mayo Clinic. Dry eye happens when your eyes either don’t produce enough tears or the tears they do pump out aren’t up to moisturizing par, and its symptoms are the definition of not fun, including dryness (duh), stinging, burning, pain, and more.

On top of the elevated dry eye risk that comes with wearing contacts, failing to clean, store, and otherwise handle your contact lens case as you should can set you up for additional problems, like various infections, Vivian Shibayama, O.D., an optometrist at UCLA Health.

To help you avoid this, here are contact lens case mistakes you might not even realize you’re making that could compromise your eye health.

1. You don’t wash your hands before touching your contact lens case.

If you want a gold medal for how you use your contacts, you’ve got to keep anything related to your lenses as clean as possible. That’s why it’s so important to wash your hands with soap and water before handling your contact lens case, Alisha Fleming, O.D., an optometrist at Penn Medicine.

If you don’t wash your hands before you touch your case, you could deposit microorganisms from your hands onto or into it, possibly making it easier for pathogens to get in your eyes and cause irritation or infection, Dr. Fleming says. For example, you could wind up with an issue like pink eye (also called conjunctivitis), which can happen when things like bacteria, viruses, or allergens inflame or infect your conjunctiva, the thin membrane that covers your eyelids and the whites of your eyes, according to the Mayo Clinic. This can lead to all sorts of unwelcome symptoms like redness, itchiness, a strange gritty sensation, discharge, or tearing, the Mayo Clinic explains.

Clearly you want to avoid this one at all costs, so be sure to wash your hands before touching your case. Of course, this might not help much if your case itself is gross, which brings us to our next point.

2. You don’t wash your case after every use (or at all).

If you’re being totally honest, does your contact lens case have a solid build-up of unidentifiable gunk on it? Or maybe even a light sprinkling of harmless-seeming lint? Yeah, that’s bad.

“Your contact lens case is like a little petri dish,” say Jennifer Fogt, O.D., an associate professor in the College of Optometry at The Ohio State University. “Bacteria can get in there and grow, and if you’re not cleaning your case regularly, you’re just reintroducing that back into your contacts when you put them in the case at night.”

There’s no official word on how often you should clean your contact lens case, but the American Optometric Association (AOA) suggests that you follow your solution manufacturer’s guidelines. Many recommend that you clean out your case after every use. That means dumping out the old solution, rinsing the case with fresh solution, wiping it down with a clean tissue, then letting it air-dry with the caps off, the AOA says.

3. Whenever you do wash out your case, you use tap water instead of contact lens solution.

When you think of how to wash something, your first instinct might be to splash on some water as step one. That’s usually a good move, but not when it comes to your contact lens case.

Introducing your contacts to tap water has been linked with an increased risk of developing Acanthamoeba keratitis, a severe corneal infection that can lead to permanent vision loss, according to the Centers for Disease Control and Prevention (CDC). “It is a scary and very serious infection,” Dr. Shibayama says.

Acanthamoeba keratitis happens due to a microbe that can hang out in tap water (and distilled water, too), stick to your contacts, and cause an infection. If this happens, you might experience eye pain, redness, blurry vision, the sensation that you have something in your eye, sensitivity to light, and excessive tearing, according to the CDC.

Since improper contact lens use is a big risk factor for Acanthamoeba keratitis, it’s key to make sure you’re not letting tap water touch anything having to do with your lenses, including your case.

4. You don’t buy a new contact lens case every three months.

Unless you’ve lost your contact lens case, buying a new one probably isn’t at the top of your to-do list. Still, the AOA recommends that you get a new case every three months, even if your current one looks chef's kiss-level immaculate.

Bacteria and other microorganisms can produce a substance called biofilm that can form in your case and help bacteria “hide” from the disinfectant in your contact lens solution, the AOA says. That's...actually kind of interesting, because who doesn't love scientific subterfuge, but the point is that it can be bad news for your eyes. You can’t actually see this biofilm, so it’s really best to replace your case every three months, whether or not it looks like it needs it.

5. You top off the old solution in your case instead of squirting in fresh liquid every time.

When it’s full of liquid, your contact lens case is warm and moist. This just so happens to be the kind of environment in which microorganisms like bacteria and fungus typically thrive. When you add more solution to your case, you’re pushing whatever may have been growing in there deeper down, Dr. Fogt says, where it can still glom onto your contacts. “You just create an environment where you’re growing more stuff that’s bad for you in your case, putting your lens into it, and then putting that in your eye,” Dr. Fogt says.

Instead of doing this, make sure you get rid of all the old solution in your case every time, then proceed with washing it out before you eventually add new solution to store your contacts.

6. To try to extend how long you can use your contacts, you store old ones in your case with fresh solution.

Throwing some barely-hanging-in-there lenses into your contact case with fresh solution should help revitalize them, right? Unfortunately, no. “Contact lens solution does not extend the suggested wear cycle of the contact lens,” Dr. Fleming says.

For the record, you should throw out your contact lenses on time whether or not you actually wore them for the full use period. For example, if you break out your 30-day contacts but end up wearing your glasses for 15 of those days, you still should ditch the contacts 30 days after you started using them, Dr. Fogt says.

7. You keep your case in the bathroom instead of in a less humid environment.

Proximity to the bathroom sink seems like a good thing, right? Especially since you’re going to actually starting cleaning your case as often as you should? The problem is that your case is at the greatest risk of becoming contaminated when you keep it in a humid environment like your bathroom, the AOA says.

Not only that, your toilet creates what’s known as a “toilet plume” that can spray pathogens like E.coli and salmonella into the air when you flush, the AOA says. If your case is lying out in the open, those little droplets can land on it, where you can transfer them all too easily into your eyes.

This doesn’t mean you’ll definitely wind up with some sort of intense eye infection simply because your contact lens case is in the bathroom. After all, tons of people do this for years without issue, and maybe you’re one of them. But if you're concerned and want to keep your eyes as safe as humanly possible, aim to store your contact lens case in a clean, low-humidity environment while your lenses are disinfecting.

If you use contacts and are dealing with any strange eye symptoms, see your eye doctor and be honest about your contact lens habits.

Many eye problems have similar symptoms, whether you’re dealing with dry eye, pink eye, Acanthamoeba keratitis, or something else entirely. Instead of trying to self-diagnose and tackle the problem alone, see your doctor. That way you’ll know exactly what you’re dealing with and can find the quickest path toward healing.