Toric contact lenses are usually prescribed to correct astigmatism, a common vision problem. Toric lenses have special curves to help compensate and correct for astigmatism.
Function
Regular, spherical, contact lenses have a single power for myopia, nearsightedness, or hyperopia, farsightedness. Toric contact lenses also have an additional power that is designed using curves at different angles to correct for astigmatism.
Soft and Hard Lenses
Contact lenses designed to correct astigmatism are made from the same material as regular contact lenses. Toric contact lenses are available in soft silicone or in a rigid plastic called gas perm or RGP. According to the American Optometric Association, RGP lenses last longer and provide excellent vision, but soft lenses are more comfortable and stay in better. An eye care professional will determine which type of lens works best based on a person's prescription.
The Lenses
Soft and RGP toric lenses need to sit in a specific way on the eye to provide the clearest vision. The lenses contain a ballast which makes the lens slightly thicker at the bottom. The extra weight causes the lens to rotate into proper position. The additional thickness is subtle but visible if a person looks closely. Some toric lenses have tiny slash marks on the bottom of the lens, usually two or three vertical lines that indicate the bottom of the lens.
Developments
Many changes have been made to toric contact lenses in recent years as new lenses have been made available in disposable, tinted, extended wear and bifocal contacts. While toric lenses were not suitable in some cases in the past, they have become beneficial for more patients.
Cost
Because of the additional design and technology, toric lenses cost approximately one third to two thirds more than a standard spherical contact lens. While the cost may seem prohibitive, the difference in vision correction is remarkable if a person has enough astigmatism to warrant a toric contact lens prescription from his eye doctor.
