complication, but often lenses with deposits need to be replaced. Rarely, one can develop an allergy to lens material itself, and trying a different brand, or switching to a rigid type of lens may help.A more unusual but common allergy problem is phlyctenulosis, the development of an allergy to bacteria present on the edge of the eyelid. These bacteria produce toxins that become trapped in the tears, especially beneath a contact lens.Lens depositsProtein deposits can frequently form on both soft and rigid types of lenses. With soft lenses, the regular use of enzyme cleaners as well as proper disinfection and daily cleaning of lenses can help prevent the protein deposition. Rigid lenses may develop deposits especially during seasons with high pollen counts, and polishing the lenses usually will buff off any deposits.When a lens develops deposits, the eye can become irritated, itchy, and red. Wearing time may be decreased, and the vision may be somewhat blurred. Complications such as "giant papillary conjunctivitis (GPC)" may occur, which can limit the use of contact lenses for an extended period of time. Once unremoveable deposits form on a soft lens, the lens usually has to be replaced. Rapid development of deposits on lenses is a valid reason to consider disposable lenses. Some contact lenses on the market are designed to be resistant to deposit formation.Contact Lens Wear ComplicationsUlcerative Bacterial Keratitis (UBK)The development of a corneal ulcer (an infection of the cornea) unfortunately is a common complication of contact lens use. Both Rigid Gas Permeable (RGP) and soft hydrogel lenses are associated with significant problems though hydrogel lens wearers are more prone to infection than are wearers of RGPs. This is partly because the soft lens provides a good surface for bacterial attachment. Additionally, RGPs are more easily cleaned and are less prone to bacterial adherence than soft lenses. Disposable contact lenses worn...
