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 normally occur because the eyes focus light rays incorrectly in relation to the retina. Nearsightedness causes light rays to focus in front of the retina, while farsightedness causes light rays to focus behind it.
Astigmatism is a different problem altogether. Astigmatism means that the cornea, lens or the eyeball as a whole is oddly shaped compared to a normal eye. The physical distortion is small and undetectable by others, but small differences in the eye produce a large effect for your vision. Light rays end up scattering in many different directions–not just ahead of, behind, or on the retina. Blurred vision is the unfortunate result of this distortion.
The manner in which astigmatism scatters light made it difficult to produce contact lenses to fix the problem. Toric lenses solved that problem by combining two different geometric shapes so as to focus light properly. Ordinary contact lenses are shaped like half of a sphere, while toric contact lenses combine a spherical shape with a toroidal (donut shaped) one. This unique shape solves astigmatism’s light scattering problem.
Toric contact lenses are made using the same materials as other contact lenses, despite their different shape. They can be soft, rigid gas permeable (RGP), or hard. But unlike other contact lenses, toric lenses cannot be allowed to rotate around the surface of the eye. Rather, the toric lens shape must remain firmly in place so it can correctly prevent light from scattering.
Toric contact lenses can also be designed to fix more than one vision problem simultaneously, such as astigmatism and farsightedness. This flexibility and unique shape of toric lenses makes them more difficult to manufacture correctly, and eye exams and fitting can be more complicated.
Toric lenses may be more expensive as a result. For people who only have a mild astigmatism the extra expense might be avoided by using regular contact lenses. The cornea will to some extent conform to the shape of the lens and minimize light scattering. 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 there are sure to be great toric contact lenses to fit your budget and lifestyle.
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.
categories: toric contact lenses, toric lenses, contact lenses, eyewear, vision care
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