Astigmatism is quite a common condition caused by irregularities in the cornea or lens of the eye, and distorts the image on the retina. Those who have a slight blurred vision are not even aware that they have astigmatism. In the case of more severe astigmatism, everything is blurry at a distance, and it becomes impossible to ignore the condition. People who suffer from astigmatism can have their vision improved by the usage of toric lenses.
Typically, astigmatism is a hereditary condition, where the shape of the eye is irregular. The normal spherical shape of the cornea, or the lens, of the eye is more oblong – football ball like. Astigmatism may accompany Myopia (nearsightedness) or Hyperopia (farsightedness). Astigmatism can usually be corrected with toric contact lenses among other methods, such as glasses and refractive surgery.
Types Of Astigmatism
There are basically two variations of astigmatism – regular astigmatism and irregular astigmatism.
Regular astigmatism is usually easier to correct. In it, the meridians in which the two different curves are, are located 180 degrees apart. In the case of irregular astigmatism, which is more difficult to correct, the two meridians may be more, or less, than 180 degrees apart, or there may be more than two meridians. Correcting this is quite complicated and depends on the extent of irregularity, and the cause behind it.
Toric lenses can easily correct regular astigmatism, whereas irregular astigmatism, being more complicated and difficult to correct, requires custom made contact lenses. Astigmatism, whether slight or severe, should not be ignored, as it not only gives you a blurred vision, it also gives you headaches and eyestrain.
Children too develop astigmatism and are either generally not aware, or do not complain. Neverheless, it makes their life quite difficult. It is best that you have your child's eyes tested every year, and if diagnosed with astigmatism, can have this condition corrected with toric contact lenses.
Toric Lenses For Astigmatism
The earlier belief that people with astigmatism could not wear contact lenses, and only Rigid Gas Permeable (RGP) contact lenses could correct astigmatism is no longer true. Soft contact lenses that can correct astigmatism are called toric contact lenses, and they can do an equally good job of correcting your, and your child's, astigmatic vision.
They have a special inbuilt correction that also has correction for either nearsightedness, or farsightedness, depending on your condition. In the past soft toric contact lenses were not available in disposable, frequent replacement, multi-focal, or colored varieties. Today, you have many options available to correct your astigmatism with toric contact lenses, unless you have an especially complicated prescription.
Soft toric contact lenses are made from the same materials regular contact lenses, which are also known as spherical contact lenses, are made from. To take care of astigmatism, and either myopia or hyperopia, toric lenses are created to have two different powers in them with curvatures at different angles.
The normal 'spherical' contact lenses have the same power all around, and so it does not matter if the lens rotates in the eye. In the case of toric contact lenses, due to the two different powers, there is a need to keep the lens from rotating, to maintain the best visual acuity. For this, they are 'ballasted' by making them heavier at the bottom. This mechanism keeps the lens reliably stable, providing you with a crisp vision, when you look around or blink.
The fitting of the soft toric contact lenses will take more time and expertise of your optometrist than for the normal regular contacts. Some eye care practitioners may fit you with high powered spherical soft lenses to correct your mild astigmatism. The results will vary from person to person, and by a trial and error method. It is best to opt for toric contact lenses, even though the cost of fitting, and the cost of the lenses themselves, will be more than the spherical lenses.
Types Of Toric Contact Lenses
When looking for toric contact lenses, you have a choice of color and disposable lenses.
Toric contact lenses are available in many colors that change or enhance your natural eye color. Most colored toric contact lenses are non-disposable conventional contacts, and only some colors are available as disposables.
The four types of colored toric contact lenses are visibility tints, enhancement tints, opaque color tints and light-filtering tints.
Disposable lenses were designed to be worn for a specific period and then to be disposed of. They are more hygienic than traditional lenses as substances that are normally found in your tears, like protein, calcium, and lipids, can build up on your lenses, causing discomfort. The alternate to disposable lenses is to clean your conventional toric lenses regularly.
If you are suffering from astigmatism, it is best you visit your optometrist for a fitting of toric contact lenses – the best option available today.