The Health Nut Blog

Toric Contact Lenses

For many years after their introduction contact lenses were able to easily correct nearsightedness or farsightedness, but nothing else. Changing the point at which light rays focus is a fairly straightforward task, though it does require careful crafting of the lens. But correcting some forms of astigmatism still required wearing glasses. Toric contact lenses ultimately solved that problem.

Nearsightedness causes light rays to focus in front of the retina. Farsightedness causes light rays to focus behind the retina. But, astigmatism denotes a condition in which the cornea, lens or the eyeball as a whole is misshapen. The effect is subtle, but small differences in the eye produce a large effect. Light rays get scattered in different directions, not just ahead of or behind the retina. Blurred vision results.

That multiple direction effect makes it more difficult to produce contact lenses (or even glasses) that will correct the condition. Toric lenses solve the problem by combining shapes. Regular contacts are shaped like a portion of a sphere. Toric lenses combine a spherical surface with a toroidal surface. A donut for example is a toroid, so is a cylinder when it wraps around to touch itself.

Though shaped differently, toric lenses are made of the same materials as other contact lens types. So, they can be soft, RGP or hard. But because they are a combination of shapes they can't be allowed to rotate around the eye like ordinary contacts. Also, all toric lenses are designed with multiple powers to tackle more than one vision problem at the same time, such as astigmatism and farsightedness together. Those features make them more difficult to manufacture correctly and eye exams and fitting are more complicated.

As a consequence, toric lenses tend to be more expensive and so are doctor visits to prescribe them. For some with only a mild astigmatism the extra expense can be avoided by using regular contact lenses. To a degree, the cornea will tend to conform to the shape of the lens. If the astigmatism is mild enough toric lenses may not be necessary. Only your eye care professional can say for sure, after an exam.

For those who do need toric lenses, the full range of choices is available and they work very well. Often, those with an astigmatism require contacts that achieve multiple goals. Multifocal lenses are an option. Toric lenses are available in disposable lens types, whether 2-day or 7-day or even 30-day. Many extended wear lenses come in a toric option, too.

For those who want to add a bit of color to their contact lens, toric styles also provide that range of options. Visibility tints make lenses easier to see, making them easier to handle and harder to lose. Enhanced or full color tints can subtly influence eye color or change it entirely. Colored toric lenses are available for that, too.

Check out the full catalog of choices in toric contact lenses and you're sure to find one just right for you.

# posted by NeilG @ 8:37 PM