People wearing contact lenses should never lose sight of the fact that they are “medical devices” that warrant careful use. Contacts should be worn as prescribed and cleaned as recommended to prevent unnecessary and potentially sight-threatening conditions. Chief among these in recent years is “Acanthamoeba keratitis,” a potentially very serious infection caused by a microorganism commonly found in soil and fresh water, among other habitats. Problems can arise when tap water is used in cleaning and disinfecting contact lenses and lens cases. If this form of amoeba were to invade the cornea, infection and possible sight loss might ensue. It more than pays, therefore, to be conscientious and vigilant when it comes to contact wear and cleansing habits. Symptoms of Acanthamoeba keratitis include red, painful eyes with sensations of a foreign body, tearing, and light sensitivity. Contact lenses can be an exciting alternative to glasses because they give the wearer a glasses-free look and hassle-free wear all day long. Wearing contact lenses is different from wearing eyeglasses because the lenses are worn directly on the eyes. Adherence to a prescribed wearing, cleaning, and replacement schedule is important.