Can I wear Contact Lenses if I have astigmatism?
Yes! There was a time when people with astigmatism had great difficulty finding suitable lenses. These days, not only may lenses be worn; they also provide superb comfort and stability of vision. Astigmatism can be corrected with both soft lenses or rigid lenses (Gas Permeable).
What are Toric Lenses?
A toric lens is a soft lens designed for people with astigmatism. Toric lenses correct astigmatism by using different optical power and focal length than a standard lens. Standard lenses have a spherical surface. In a “normal" eye, the cornea and lens are smooth and the curves are equal. When you have astigmatism, the curves are not equal, and when light rays pass through your cornea and lens, they do not focus correctly on your retina, creating what's called a refractive error. Toric lenses have different powers in different meridians and it is often described that a non astigmatic cornea looks like a 'football', whereas a toric cornea looks more like a rugby ball.
Toric Lens Options
Small amounts of astigmatism (< 1.00D) can often be ignored with soft lenses - most people will experience vision only slightly less clear than their glasses. However if you want that corrected there are now lenses capable of that - even daily ones. Dailies Aquacomfort Plus Torics, for example, can correct up to 2.00D of astigmatism easily and may be just what you need to sharpen up your vision.
For greater amounts of astigmatism (greater than 2.00D) the astigmatism will often be corrected with either a standard Gas Permeable lens, which are very effective at correcting astigmatism , or by using a special soft lens called a Soft Toric lens. Without this correction the vision can be quite blurred. These lenses are often replaced on a monthly cycle. A good example of a soft toric lens that can correct up to 3.00D of astigmatism, and is replaced monthly, is Acuvue Oasys for Astigmatism.
For astigmatism over 3.00D, the astigmatism could be correct with a specialised soft toric lens or possibly toric gas permeable lens.
Soft toric lenses have the extra astigmatism power 'worked on' the lens so that it corrects your astigmatism like glasses would.
"So why does my Optometrist say no?"
There are some disadvantages to soft toric lenses. Your astigmatic power has to be worked onto the soft lens and maintained at a certain angle - the lens cannot be allowed to spin around like an ordinary soft lens could - in order to properly correct your vision. At the same time any soft lens has to be able to move a little in order to allow tears and waste to move out from under the lens. This necessary movement of the lens can cause the vision to blur slightly. The greater the degree of astigmatism, the more noticeable this effect can be.
This effect can be annoying, for example, when you are operating a VDU. However, millions of people wear then successfully for social use, driving and sport and are very happy with the level of vision that they obtain.
The other disadvantage is that soft toric lenses are generally more expensive than standard soft lenses - roughly twice as expensive, and take more time with the Optician in initial fitting.
In conclusion - the pros and cons will have to be weighed up carefully with your Optician. He will discuss with you what you want them for, your lifestyle and take into consideration your amount of astigmatism and other clinical information. Only then can you decide, in conjunction with your Optometrist, if you should proceed or not.
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Author: John Dreyer Optometrist Bsc(Hons), MCOPTOM, DipCLP
Created: 28 Apr 2015, Last modified: 18 Apr 2019