eye disorders
Contact Lenses
Introduction
Contact lenses provide better peripheral vision than do eyeglasses and can be prescribed to correct the following: Overview of Refractive Error None Overview of Refractive Error None Overview of Refractive Error None Overview of Refractive Error None Aniseikonia (a difference in image size) Aphakia (absence of the lens) after cataract removal Keratoconus (a cone-shaped cornea) Either soft or rigid lenses are used to correct myopia and hyperopia. Toric soft contact lenses (which have different curvatures molded onto the front lens surface) or rigid lenses are used to correct significant astigmatism; they are satisfactory in many cases but require expert fitting. Contact lenses are also used to correct presbyopia. In one approach, termed monovision, the nondominant eye is corrected for near vision (reading) and the dominant eye is corrected for distant vision. Rigid and soft bifocal and multifocal contact lenses can also be successful, but the fitting procedure is time-consuming because precise alignment is essential. Neither rigid nor soft contact lenses offer the eyes the protection against blunt or sharp injury that eyeglasses do. 