Variety of Contact Lenses (contacts): From extended wear lenses to daily wear (disposable) lenses for vision correction and astigmatism

Definition of contact lenses (contacts)

A contact lens (aka contacts) is a thin lens of plastic worn on the eyeball and used to improve vision, treat refractive error (farsightedness and nearsightedness) or to correct or treat disorders. Corneal lenses cover just the cornea of the eye and float on a film of tears. Contact lenses are made of soft plastic can be worn for longer periods of time than the hard-plastic models. Scleral lenses, covering the entire eye, are occasionally used to treat eye injuries or infections. Colored contact lenses (aka color contact lens or tinted contact lenses) are used to change the eye color. Other contact lenses are used for monovision.

Spheric, aspheric, toric, bi-toric, bifocal and multifocal contact lenses for vision correction

Spheric contact lenses are prescription lenses with smooth spherical surfaces that bend light rays equally in all directions. Aspheric contact lenses are used for borderline astigmatic patients and emerging presbyopes. Toric contact lenses are lenses that contain a cylinder component to correct astigmatism by bearing two different optical powers at right angles to each other. Toric and bi-toric contact lenses are used to correct residual astigmatism. These lenses may be thicker in one meridian to enable the lens to maintain proper orientation on the eye. There are also bifocal contact lenses.

Options in contact lenses: From daily wear/disposable contact lenses and extended wear lenses to hard and soft contact lenses

Daily wear contact lenses are worn only during waking hours. Disposable lenses are intended to be worn for a certain time period - daily, weekly, bi-weekly, monthly - and then discarded. Frequent replacement lenses (frequent use lenses) are thrown away monthly or quarterly. Extended wear contact lenses can be worn continuously, even while sleeping, up to a maximum number of days, usually one to seven days. Extended wear lenses are manufactured from a high water content material and/or a thin center thickness to allow maximum oxygen transmission. Hard contact lenses are manufactured using rigid materials that essentially provide a new front surface for the eye. These lenses help in the correction of astigmatism because the tear film of the eye fills in the gap between the lens and the irregularly shaped cornea. Rigid gas permeable lenses (RGP) contact lenses are durable contact lenses made of polymers that transmit oxygen and allow longer wearing times than other rigid lenses. Because RGPs do not contain water, they resist deposits and are not prone to harboring bacteria. These lenses are large in diameter to increase comfort. Soft contact lens: are made from flexible plastic, these lenses absorb water and thus enable greater amounts of oxygen to pass through the lens to the cornea. Soft lenses are more comfortable for most wearers than hard lenses, and most often prescribed lenses today. Contact lenses are available from a wide variety of sources. Contact lens discount centers offer cheap contact lens and discount contact lenses. A free contact lens eye test is available at VisionRx.com.

Contact lens care and cleaning

A variety of cleaning methods are available for contact lenses, including cleaning, rinsing and disinfecting. Contact lenses are cleaned by disinfecting and rinsing contact lens solution or lens cleaner. Enzymatic cleaners to remove deposits and debris and to reduce the buildup of protein deposits on the lens surface. Toric lens care may be slightly more involved. Contact lens wearers should follow the wear and care schedule keeping lenses free from contamination, and use cleaning, disinfecting and rinsing solutions as directed. Lubricant eye drops to soothe and moisten lenses to minimize dryness and make lens wear more comfortable. Care should be taken by contact lens wearers to use eye drops specifically formulated for contacts. Other drops may stain lenses. There are also multi-purpose solutions that provide all three functions. Rewetting solutions are designed to lubricate the lenses while they are worn.

Specific Information on Contact Lens, Contact Lenses

• Contact Lens - Defined
• Encyclopedia articles on Contact Lenses
• Basic Anatomy of the Eye and the Cornea
• What’s included in a Contact Lens Eye Exam
• Choosing a Contact Lens Eye Care Professional
• Contact Lens Eye Care Resource Directories

Useful links related to Contact Lens, Contact Lenses

American Academy of Ophthalmology American Optometric Association American Council of the Blind American Foundation for the Blind Lighthouse International National Association for Visually Handicapped Prevent Blindness America

Other Eyecare Specialties at VisionRx.com

General Eyecare Laser Vision Correction Cataracts Glaucoma Retina Macular Degeneration Contact Lens Plastic Surgery Pediatric Eyecare Dry Eye Eyeglasses