Toric contact lenses arose in response to a need that could not be addressed by traditional contact lenses. For years subsequent to their introduction, contact lenses could easily correct farsightedness or nearsightedness but nothing else. Through careful crafting of the contact lens it became possible to easily change where light rays focused on the retina. But astigmatism posed a problem that was unsolvable by technology at the time, therefore requiring people with astigmatism to continue wearing glasses. Toric contact lenses ultimately solved that problem.
Vision problems usually happen because the eye incorrectly focuses light rays in relation to the retina. Farsightedness causes light rays to focus behind the retina, while nearsightedness causes light rays to focus in front of it.
Astigmatism poses a different problem. It is a condition in which the cornea, lens or the entire eyeball is shaped oddly compared to a normal eye. The physical distortion is small, but small differences in the eye create a large effect on vision. Rays of light scatter in many different directions instead of just ahead of, behind, or on the retina. Blurred vision is the unfortunate result of this scattering.
The scattering of light that occurs in astigmatism is what makes it more difficult to produce contact lenses to fix the problem. Toric contact lenses solve this problem by combining different shapes in order to focus light properly. Regular contact lenses are shaped like half a sphere, but toric lenses combine a spherical surface with a donut shaped (toroidal) one. This unique shape solves the light scattering problem.
Toric contact lenses are made of all the same materials as other contact lenses, despite their different shape. They can be hard, soft, or rigid gas permeable (RGP). However, unlike other contact lenses, toric lenses cannot be allowed to rotate around the surface of the eye. The toric lens shape must remain firmly in place to prevent the scattering of light.
Also, toric contact lenses can be designed with multiple capabilities to address more than one vision problem at the same time, such as astigmatism and nearsightedness. This makes toric contact lenses more difficult to manufacture correctly, and eye exams and fitting are more complicated.
Toric lenses are sometimes more expensive as a result. For people with a mild astigmatism the extra expense may be avoided by using ordinary contact lenses. The cornea can to some extent conform to the shape of the lens and thereby minimize the scattering of light. In fact, toric lenses may not be necessary at all for mild astigmatism--but only your eye care doctor can say for sure after administering an exam.
For people end up needing toric contact lenses, there are many options available. You can purchase single or multifocal lenses. Toric lenses are also available in the same types as regular lenses--disposable, single day wear, weekly wear, monthly wear, and even extended wear.
If you suffer from astigmatism, then consider choosing from a range of toric contact lenses that fit your budget and lifestyle needs.
Want to find the best toric contact lenses for you? Then visit David Long's toric lensessite and choose the best ones for your needs.