Toric Contact Lenses: What Are They and How Do They Work?
There are many different types of contact lenses on the market to improve vision. Toric contact lenses are in a special category of lens that is used to correct for a common vision condition called astigmatism.
Unique in their design, toric lenses can be well worth the investment for those who prefer contact lenses over eyeglasses.
What Are Toric Contact Lenses?
First, what does toric mean when applied to contacts? Toric comes from the word torus, which means “bulge.” In geometry, a torus is a three-dimensional hollow cylinder or tube shaped like a doughnut.
Toric contact lenses are unique due to their shape. They are designed differently from other types of contact lenses to correct for specific vision issues.
While all contacts are round (spherical) in shape, there is a subtle difference with toric lenses. The comparison is often made that standard contacts look like they were sliced off the perimeter of a ball.
Toric lenses, on the other hand, are slightly cylindrical as though they were sliced from the edge of a doughnut. This approach produces a lens with the multiple focal lengths needed for treating astigmatism.
Toric Contact Lenses for Astigmatism
Toric contact lenses work well for people with corneal astigmatism, particularly those who are also nearsighted or farsighted. Soft toric lenses correct for all these conditions.
Astigmatism is an imperfection in the eye’s cornea or lens that affects one in three people. It occurs when these structures are irregularly shaped. For example, in corneal astigmatism, the cornea has a shape more similar to an egg or American football rather than a round basketball.
Astigmatism is hereditary, which means it passes from generation to generation within a family. It can also be the result of an eye disease, injury or surgery.
Astigmatism can affect one or both eyes, and can improve or worsen over time. It’s important that you have regular eye exams, just as with any other vision condition.
How Astigmatism Affects Vision
Clear vision depends on a number of factors, including the cornea (clear dome at the front of the eye) and the lens. Astigmatism can cause light rays to fall either in front of or behind the retina, resulting in blurry vision.
People with astigmatism may experience blurred or distorted vision, eye strain, squinting, headaches and difficulty seeing at night.
How Do Toric Lenses Work?
Corrective contact lenses refocus light onto the retina in the back of your eye so that you can see more clearly. The type of lens that is prescribed depends on the particular vision issue being treated.
In addition to correcting for astigmatism, toric lenses can also correct for nearsightedness or farsightedness. That’s because these unique lenses have two different powers, or levels of correction. One power corrects astigmatism and the other power corrects distance vision. Standard contact lenses have just one power throughout the lens.
Contacts must remain in their proper place on the eye to provide consistent, comfortable and clear vision. This is particularly true with toric lenses. Normal blinking can cause contacts to shift slightly. Torics are made with physical features to stabilize and keep them in place. These include thicker areas on the lens, weighted sides and a flat bottom.
Pros and Cons of Toric Lenses
If you are diagnosed with astigmatism, choosing the best contacts for you starts with a review of the available options, including toric lenses. Some toric pros and cons to consider include:
- Toric lenses correct for corneal astigmatism as well as distance vision.
- There are a variety of brands from which to choose for a customized fit.
- Torics are made from soft hydrogel or silicone hydrogel material.
- Daily, biweekly or monthly wear options are available.
- olored toric lenses are available.
- Toric contacts usually cost more than regular contact lenses.
- You may need to try more than one brand of torics to find the one that works best for you.
- You may need several fittings initially, which can be time consuming.
- Toric lenses are more likely to shift with blinking, momentarily affecting vision.
- There are power limitations for treating astigmatism and distance vision.
Getting Started with Torics
As is always the case with contact lenses, you must get a prescription for torics from an eye care professional. An optometrist or ophthalmologist will first do a comprehensive eye exam that includes several different tests, including one for astigmatism.
If you are diagnosed with astigmatism, your eye care provider will discuss various options with you. If you choose toric lenses, your provider will select a specific brand and do a lens fitting. This part of the process may be repeated until you find the most comfortable lens fit for you. The provider will also show you how to put in your toric lenses, outline a care routine and provide other tips for adjusting to your new contacts.