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 The Cornea is responsible for focusing light that enters the eye. Any irregularity in the cornea can distort vision and result in significant visual impairment.
Custom contact lenses are available if the patient can't wear regular contact lenses because of problems such as an irregularly shaped eye or too much astigmatism. The patient and their practitioner might consider custom contact lenses if regular contacts are uncomfortable or cause vision problems.
Custom-made contacts are available in both rigid gas permeable (GP) and soft lens materials, and may be able to provide sharper vision and greater wearing comfort than regular GP or soft lenses.
Once successfully fit many patients report an improvement in the quality of their life.
Gas Permeable Contact Lenses (GP) are made from plastic polymers that allow the flow of oxygen to the eye.
GP lenses can be fabricated to fit unusual corneal surfaces. They are often an excellent solution for patients with keratoconus or unusual corneal curvature from natural causes, an eye injury or from unsuccessful Lasik surgeries or other refractive surgeries.
Many of these patients have very poor vision in spectacles or soft lenses, yet have the ability to achieve 20/20 vision with well designed GP contact lenses.
Most custom contact lenses were traditionally made of rigid gas permeable lens materials. Today, custom lenses also are available in soft lens materials, including new highly oxygen-permeable silicone hydrogel polymers.
Some custom soft contacts are now made with advanced silicone hydrogel materials that allow more oxygen to reach the eye than conventional soft lens materials. For example, Contamac, a U.K.-based company, recently received FDA approval to supply a proprietary silicone hydrogel material to optical labs in the United States for the fabrication and sale of custom soft lenses. The material, called Definitive, can be lathe-cut in a manner similar to how rigid gas permeable contacts are manufactured, for a virtually unlimited degree of customization.
ABB OPTICAL GROUP manufactures both Definitive lens by ABB OPTICAL GROUP and also the KeraSoft® lens in the Definitive material.
As with custom rigid GP lenses, fitting soft and silicone hydrogel custom contact lenses is more complex than a conventional contact lens fitting and often involves the use of special equipment to measure corneal topography and higher-order aberrations to assist in the design and fitting of the lenses. | 
