Author: Erich Shrefler
If you have blurred vision when looking at objects up close, far away, and in between, it may be astigmatism. Astigmatism causes blurry vision due to an irregularly shaped cornea. Most people have some slight astigmatism but not always enough to cause vision problems.
Your Cornea and Astigmatism
Astigmatism is a type of refractive error. Your cornea bends, or refracts, light as it enters your eye to focus it on the retina. In order to properly focus the light, your eye needs to be spherical in shape. With astigmatism, the cornea is oblong or oval shaped, more like a football. When the irregularly shaped cornea bends the light it creates two or more focal points, rather than one clear focal point, causing the image to be blurry.
Astigmatism can occur alone or in combination with nearsightedness (myopia) or farsightedness (hyperopia). Symptoms include:
- Distortions in vision making it difficult to make out fine details up close, far away, and in between
- Blurred vision
- Eye strain
Children can be born with astigmatism, or the condition can be caused by trauma to the eye due to an injury or surgery. Keratoconus is a disease of the eye that causes progressive thinning of the cornea and can cause astigmatism.
If you are experiencing the symptoms of astigmatism or any change in your vision, it is important to see your ophthalmologist right away. These can be symptoms of a more serious eye condition or health problem.
Astigmatism in One Eye
When vision is different between your two eyes, your brain chooses the better of the two images, ignoring the bad eye. The eyes do not work together properly and depth perception is affected.
In young children, whose brains are still developing, astigmatism in just one eye can cause lazy eye (amblyopia). Left untreated amblyopia can cause permanent vision loss in the affected eye.
Eyeglasses or contact lenses are typically prescribed for people with astigmatism. In the past, soft contact lenses were not an option for astigmatism. Today there are soft contacts available for astigmatism, but they are more difficult to make and cost more than other soft lenses.
Corrective lenses improve your vision while you wear them, but they do not truly correct the astigmatism. Refractive surgery, such as LASIK or PRK, reshapes your cornea correcting the refractive error. If you are also nearsighted or farsighted, the surgery can correct that at the same time, giving you clear vision without the need for glasses or contacts.