Caring for your contact lens and the contact lens case correctly is critical to maintaining the ongoing health of your eyes. By improperly cleaning your contact lens case, you are allowing harmful bacteria to build up on your contact lens. Given time, this buildup will begin to irritate your eyes. If left uncorrected, this can seriously damage your visual health.
To avoid this, simply cleanse your contact lens case according to the instruction given by the manufacturer. This will usually include rinsing the case out at regular intervals with a specified cleansing solution or using very hot tap water and then letting the case air dry.
Remember to only use commercial cleansing solutions recommended by your eye care practitioner. Homemade remedies fail to properly destroy the bacteria that are found in contact lenses (and accessories). One of the most destructive known eye infections comes from an ameba named Acanthamoeba. It enters the eye through failure to properly cleanse, handle, and store contact lenses and cases.
In addition to proper cleansing/disinfecting the contact lens case, most eye care practitioners recommend discarding your case every month or every three to four months. Although this may seem like a lot, most designer contact lens cases can be purchased for less than $10 with very basic screw-top cases being available for under $2.