If you wear contacts, you might be wondering how bad it really is to swim with your lenses in. After all, you can’t always plan ahead for this type of summer fun. A day at the beach can have you chasing waves instead of building sandcastles. Or a friend’s invite for a kids’ pool party can quickly turn into an adult swim party.

Not to mention, if you’re used to wearing your contact lenses and you don’t have a pair of glasses to wear in public, you might suck it up and swim with your lenses in. At least this keeps you from bumping into walls and people, right?

Unfortunately, swimming with your contact lenses is not a good idea. Whether it’s a chlorinated swimming pool or natural lake, here are four convincing reasons why you shouldn’t swim with your contacts in.

1. Your eyes will feel irritated.

The FDA recommends keeping contact lenses away from water, whether it’s fresh, chlorinated or from the tap. Water contains many different viruses and microbes that can make people sick. When you swim with your lenses in, these viruses and microbes can attach to your contacts and cause problems. Also, swimming causes the lenses to shrink around the eye, causing significant irritation.

2. Your chances for an eye infection increase.

Soft lenses are porous, making it easy for bacteria to slip through and sit on the surface of your eye. If you wear your lenses while swimming, you’re essentially allowing chemicals and bacteria to lodge inside the lens and create an infection. If you absolutely have to wear your contacts, we recommend wearing goggles, removing the lenses after swimming or using disposable lenses.

3. You can end up with a parasite called Acanthamoeba.

Acanthamoeba is a parasite that lives in freshwater and soil. It can attach to your contact, causing your cornea to become infected and inflamed. Without prompt treatment, acanthamoeba can lead to permanent vision loss or a cornea transplant. This is the same parasite that can affect contact wearers who clean their lenses with tap water.

4. Your eyes will feel drier.

Water washes away the normal wear and tear film and its natural lubricating properties, making your eyes feel drier. Combine this with a shrunken lens, and it’s a recipe for redness and irritation. Plus, the chemicals in the water can cause the conjunctiva in your eye to get red, swollen and inflamed. If this happens, rewetting drops can help.

Be Smart – Don’t Swim with Your Contacts!

We know it can be tempting to swim with your contact lenses in, but we advise against it. If you have to, take your lenses out when you’re done swimming and let them soak for a while. Or, replace them with a new pair. A day of swimming is not worth a long-term infection that leaves you with permanent vision problems.