Contact lenses are medical devices worn on the surface the eye that correct vision by changing its shape. They are usually made of an oxygen-permeable polymethyl methacrylate, also known by the names Perspex and Plexiglas. However, there are other materials that can be used. The lenses are prescribed to correct refraction problems in vision. Orthokeratology, a technique that alters the corneal curve to improve vision temporarily without surgery, and decorative contact lenses (also known as colored contact lenses) are other uses for contact lens.
Contact lens care varies according to type of lens and wear schedule. Daily disposables, which are thrown away immediately after use, do not need to be cleaned. However, other lenses require regular cleaning using solution in order for them to maintain clarity and remove deposits. A wide range of solutions is available, including saline and hydrogen peroxide. Some lenses are multifocal and allow a person to see both at a distance and up close, similar to bifocals.
Some manufacturers make soft contact lenses designed to fold when applied. This increases comfort and safety. This can reduce the chance of scratching the cornea when removing the lenses. In addition, there are a variety of small tools designed to assist with the removal of contact lenses. They look like small tweezers, and work by pinching between the thumb and the index finger.