Contact lenses have improved drastically, the silicon hydrogel lenses have more oxygen permeability for the cornea and are healthier for the eye. The contact lenses should be replaced monthly or biweekly according to the type of contact lens being used. The overuse of the lenses may cause infection of the eye and damage the cornea. If your eyes get red and sensitive to light while using the contact lens, the possibility of having contact lens induced keratitis is fairly high. In this case, you should stop using the lenses and contact your eye doctor immediately.