Astigmatism is one of the most common vision problems, but most people don’t know what it is. Many people are relieved to learn that astigmatism is not an eye disease. Like nearsightedness and farsightedness, astigmatism is a type of refractive error – a condition related to the shape and size of the eye that causes blurred vision. A common way to describe astigmatism compares the shape of the eye with astigmatism to that of a football, an oval, rather than round.
In addition to blurred vision, uncorrected astigmatism can cause headaches, eyestrain and make objects at all distances appear distorted.
Signs and Symptoms…
If you have only a small amount of astigmatism, you may not notice it at all, or you may have only mildly blurred or distorted vision. But even small amounts of uncorrected astigmatism can cause headaches, fatigue and eyestrain over time.
Astigmatism usually develops in childhood. A study at the Ohio State University School of Optometry found that more than 28% of schoolchildren have astigmatism.
Children may be even more unaware of the condition than adults, and they may also be less likely to complain of blurred or distorted vision. But astigmatism can cause problems that interfere with learning, so it’s important to have your child’s eyes examined at regular intervals during their school years.
What causes astigmatism?
Usually, astigmatism is caused by an irregular-shaped cornea, the clear front surface of the eye. In astigmatism, the cornea isn’t perfectly round, but instead is more football- or egg-shaped.
In some cases, astigmatism may be caused by an irregular-shaped lens inside the eye.
In most astigmatic eyes, the irregular shape of the cornea or lens causes light rays to form two distorted images in the back of the eye, rather than a single clear one. This is because, like a football, an astigmatic eye has a steeper curve and a flatter one.
How is astigmatism treated?
Sometimes rigid gas permeable (RGP or GP) contact lenses often provide the best correction for astigmatism. But special soft contact lenses for astigmatism, called toric soft lenses, are also available.
Hybrid contact lenses are another option. These lenses have a GP center and a soft periphery to provide the clarity of gas permeable lenses and wearing comfort that is comparable to soft lenses.
And, depending on the type and severity of your astigmatism, you may also be able to have it corrected with LASIK or other types of refractive surgery.
Diagnosis & Treatment
Astigmatism is a very common eye condition that’s easily corrected by eyeglasses or contact lenses and on some occasions, surgery.
Astigmatism is caused when your eye is not completely round. Because our bodies are not perfect, astigmatism occurs in nearly everybody to some degree but for some, not to the degree that it causes blurring. Your eye is naturally shaped like a sphere. Under normal circumstances, when light enters the eye, it bends evenly, creating a clear picture on the back of your eye. In a person with astigmatism, their eye is shaped more like a football and light entering the eye is bent more in one direction than the other. This causes only part of the picture to be in focus at any given time. Objects at any distance can appear blurry and wavy. For vision problems due to astigmatism, glasses or contact lenses, and sometimes even vision correction surgery are all possible treatments.
People with undetected astigmatism often have blurred vision which can be associated with fatigue and eyestrain. While these symptoms may not necessarily be the result of astigmatism, you should schedule an eye exam if you are experiencing one or more symptoms.
Our eye doctor can diagnose astigmatism with a thorough eye exam. Astigmatism may occur in combination with other vision problems such as nearsightedness and farsightedness. Because astigmatism gets worse over times, visit our eye doctor whenever you notice changes in your vision.