FlipNSlide Contact Lens Case 3-pack used for storage and chemical disinfection of soft and hard contact lenses. Different colors make it easy to replace your lens case monthly. Molded "L" to determine between left and right wells. Why you really should replace your case monthly even if it looks clean: It's nasty in there. Even if you properly clean your case, it's growing harmful bacteria and fungi which stick to your contact lenses and find a new home on your cornea and eyelids. The common result: itchy, irritable eyes and a risky chance of infection that can cause permanent eye damage and even blindness. Start a fresh case every month. Good rule of thumb: it's dirty in 30 Pitch so your eyes won't itch.