When you hear the words “good hygiene,” what do you think of?

Washing your hands, brushing your teeth and showering probably all make the list. And if you wear contact lenses, contact hygiene should also be up there. 

Don’t worry if you’ve been slacking a little — you’re not alone. An estimated 45 million people in the U.S. wear contacts, and of these, up to 90% don’t follow the instructions for proper contact care. 

However, it’s not too late to brush off those old habits and start making contact care a priority. 

The good news? While it may take a few extra minutes every night, contact care is easy. All it takes is dedication — and an ample supply of contact solution.

Whether you’re new to contact lenses or you could use a little refresher, learn why contact lens solution is so important, how to use it correctly and how to find the brand that’s right for you. 

Also, how contact solution relates to slime.

Contact solution and infection prevention

One of the main main reasons to use contact solution is infection prevention.

Contact lenses require a little more daily care than eyeglasses — not just to help you see as well as possible, but also to protect your eyes. Cleaning, disinfecting and storing your contact lenses correctly is critical for avoiding an infection. 

The most common eye infection that stems from wearing contact lenses is keratitis. This is characterized by inflammation (swelling) of the cornea —  the clear, dome-shaped surface on the front of your eye that allows light to enter the eye. While the infectious type can be caused by bacteria, viruses, parasites and fungi, noninfectious keratitis can be the result of a minor injury or wearing your contacts for too long. 

Whether infectious or not, keratitis can cause:

But keratitis doesn’t just cause pain and slight difficulty seeing. It can lead to serious complications like open sores on the cornea (ulcers), recurring viral infections in the cornea or severe scarring of the cornea — a complication that may require a corneal transplant in order to see clearly again. 

Fortunately, there are many ways to prevent keratitis, including taking your contacts out before bed, switching to disposable lenses designed for one-day use and, of course, cleaning your contacts correctly.

SEE RELATED: Daily disposable contact lenses: pros and cons

Hygiene and the role of contact solution

When it comes to contact lens hygiene, contact solution plays a few key roles — from cleaning your contacts to storing them safely. Knowing how to take care of your lenses and your contact cases can help prevent infection and serious side effects of bacterial buildup.

Cleaning your contacts

The first step is to thoroughly wash your hands. The bacteria on your fingers can easily get transferred onto your lenses, putting you at risk for infection. Drying your hands is equally important. Water contains harmful microorganisms that can also spread easily from your fingers to your lenses. 

Once you’ve properly washed and dried your hands, you’ll move on to what the American Academy of Ophthalmology (AAO) calls the “rub and rinse” method. 

This method starts by gently rubbing the contact lens in some solution in the palm of your hand — you’ll do this for about 20 seconds on each side (unless the directions on the bottle of solution suggest longer). Rubbing gets rid of debris, tear film or allergens that may have built up during the day. Don’t skip the rubbing step, even if the bottle says “no-rub contact lens solution.” 

Then, you’ll rinse off the contact with more solution for about 10 seconds. Again, you may need to rinse longer, depending on the instructions for your specific solution.

Finally, place the lens into a clean, dry case.

The solution in your contact case

The contact lens case (and the solution inside of it) is an often-overlooked part of lens hygiene, but it’s just as important as washing your hands. Contact cases are fairly susceptible to getting contaminated with bacteria. You’re frequently reaching inside of the case, and the bacteria from your fingers can rub off on the inside of the case — and eventually, onto your lenses.

In a 2015 study, researchers found that 66% of contact lens-wearing participants had contaminated cases, and nearly 40% of those were contaminated with multiple organisms. They also found that participants who didn’t wash and dry their hands before taking out their contacts had higher contamination levels than those who did.

To correctly clean your case, start by emptying out any remaining solution. Rinse the case with fresh solution and allow it to air-dry before using it again. 

Once you place the lens into the case, fill the well of the case with solution. Depending on the particular solution, you will most likely need to let your contacts soak for four to eight hours.

Keep in mind that it’s a good idea to replace your case at least every three months in order to avoid infection and irritation.

What to do if you don't have contact solution

If you find yourself ready to take your lenses out and notice there’s no solution in sight, you’re basically out of luck. 

That’s because no other product or material works like contact solution does, and some “alternatives” are downright dangerous. Following the guidelines below can help keep you free from harm.

• Do not use water as contact solution. Water is rarely free of germs, many of which can cause eye infections. One of the most dangerous is Acanthamoeba, which is often found in lake, well or tap water. It can cause a severe version of keratitis, called Acanthamoeba keratitis, which is not just painful but is also difficult to treat and can sometimes require more than a year of treatment. 

• Resist the urge to try your hand at a homemade contact solution. No matter how tempting, avoid do-it-yourself remedies. The homemade saline in DIY contact solution is known to contain dangerous germs that can lead to blindness.

• Using eye drops as contact solution is also a no-no. Even though they’re safe to put in your eyes while you’re wearing contacts, they shouldn’t be used as a solution.

So, what else should you use? Unfortunately, the answer is nothing. 

There is no safe substitute for contact solution. 

Trying to wear contact lenses to bed to salvage them will also do more harm than good — people who sleep in their contacts have an increased risk for problems like severe red eye, infections and ulcers. 

Leaving lenses in overnight can also lead to a complication called corneal neovascularization, where there’s an overgrowth of new blood vessels into your cornea. This causes swelling, which can damage your eye to the point that your doctor won’t ever be able to fit you for contacts again. 

Your best bet is to be prepared and always have extra contact solution on hand (just make sure it isn’t expired). 

If you do run out and aren’t able to buy more contact lens solution, dispose of your current lenses and put on a fresh pair next time.