Astigmatism is one of the most common afflictions of the eye. What is astigmatism? Astigmatism is caused when either the lens or the cornea of the eye are either misshapen or slightly different in shape. This causes blurred vision at all distances. Luckily, astigmatism is easily treated with vision-correcting lenses.
The front part of the eye – the part you can touch – is called the cornea. In eyes without astigmatism, the cornea is typically spherical, or round, which allows light to enter the eye, pass through the lens and refract or bounce off the retina, sending a signal to your brain that allows it to interpret what you see. When you have astigmatism, the cornea is more oval shaped – like a football – which in turn then interrupts the signal your brain, causing blurred vision. In some cases of astigmatism it is not the cornea that is misshaped, it is the lens. This is called lenticular astigmatism.
Astigmatism most often occurs at birth (or before), although sometimes an injury to the eye can cause the same change of shape of the cornea that causes astigmatism, do the same effect – blurred vision. Astigmatism may also occur at the same time as other refractive disorders of the eye, such as near sightedness (not being to focus on items far away, or myopia) and far sightedness (not being able to focus on items close to you, or hyperobia).
People with astigmatism often report headaches as one of the first symptoms of the disorder, although blurriness is a more common problem. Because the blurriness is usually present from birth, many patients fail to recognize the problem until the headaches occur. An eye doctor using specific tools, including the keratometer and/or a keratoscope and videokeratoscope, diagnoses astigmatism.
Luckily, no matter what is at the root of astigmatism, it is easily treated with corrective lenses. There are three different lenses to treat astigmatism, and in cases of severe astigmatism, surgery is often used. Most commonly, astigmatism is addressed with corrective lenses. Until recently it was most often either glasses of “hard” contact lenses, but in the last ten years contact lenses have improved dramatically and can be used to treat most forms of astigmatism. Today, there are three kinds of lenses that can be used to treat astigmatism: hard lenses, gas-permeable lenses, and soft contact lenses (including daily, weekly, monthly, and even extended wear soft lenses). An eye doctor will make a recommendation about what can best be used to treat each case of astigmatism.
In addition to great advancements with contact lenses, surgical options to correct astigmatism have also improved. Today LASIK (laser-assisted in-situ keratomileusis) surgery is quite popular, but PRK (photorefreactive kearatectomy) and another version of laser surgery called LASEK (laser-assisted subepithelial keratomileusis) is also used. But even today, contact lenses are the most common way to correct astigmatism.
Astigmatism may be frustrating, but is a common, easily treated eye ailment. If you suspect you have astigmatism, visit your eye care professional today to be evaluated and develop a treatment plan.