You may know how to create the perfect cat eye, apply false lashes with precision and every other trick to make your eyes pop, but do you know how to avoid an infection?

With all the products we put in and near our eyes, knowing when to replace each one is vital. So while you're getting down to all that spring cleaning, here's a few things to consider tossing from your cosmetics kit.

Let's start with one you might not even think about: The contact lens case.

Hopefully you're already replacing your lenses as often as the prescription advises, but if not, consider that step one. There’s no telling the amount of bacteria and pathogens that build up on your lenses over time, so replace them religiously.

But here’s something you might not have considered: the case you store them in can be just as dangerous. "It's the number one mistake contact lens wearers make and they don't even know it," says Dr. Terry H. Berner of Broadway Eye Clinic. "Many assume their case is safe because it is used for disinfection of their contacts.  And worse, [they assume] it is safe because it simply looks clean."

If it isn’t replaced frequently, your lens case can actually do more harm than good, saturating your lenses with even more bacteria, fungi and pathogens. Replace your case every time you pop in a new pair of lenses, up to twice a month. And don’t think that scrubbing it in hot water or giving it a spin the dishwasher will do the trick, it will only make it worse. So play it safe and just spring for a new one.

Next, take a look at your eye makeup. Unlike facial creams and foundations that can have up to a 2-year shelf life, eye makeup, creams and serums should be replaced 4-6 months after you first open them.

Many cosmetic containers are conveniently equipped with shelf life indicators on the back or bottom of the packaging. Look for a small image of a container with something like 6M, 12M or 24M printed inside it. All the eye products I found in my bag were stamped with 6M, meaning I should toss them no longer than 6 months after I open the package.

If your packaging doesn’t have an indicator, make your own with a small sticker and write on its 6 month expiration date. It's better to be safe than sorry.

Finally, don’t share your eye makeup. This includes concealers and anything that gets near the eye. Always have your own tube of mascara, and if you must share, apply shadow and liner with a clean brush and concealer with a brush or your finger, not the wand.