Astigmatism » Astigmatism definition

Astigmatism is a common type of refractive error. It is a condition in which the human eye does not focus light evenly onto the retina, the light-sensitive tissue at the back of the eye. Astigmatism in the eye means that the cornea is oval like a football instead of spherical like a basketball. Most astigmatic corneas have two curves – a steeper curve and a flatter curve. This causes light to focus on more than one point in the eye, resulting in blurred vision at distance or near. Astigmatism often occurs along with myopia or hypermetropia.

How does astigmatism in the eye occur?

Astigmatism in the eye occurs when light is bent differently depending on where it strikes the cornea and passes through the eyeball. The cornea of a normal eye is curved like a basketball, with the same degree of roundness in all areas. An eye with astigmatism has a cornea that is curved more like a football, with some areas that are steeper or more rounded than others. This can cause images to appear blurry and stretched out.

Who is at risk for astigmatism?

Astigmatism can affect both children and adults. Some patients with slight astigmatism will not notice much change in their vision. It is important to have eye examinations at regular intervals in order to detect any astigmatism early on for children.

How is astigmatism diagnosed?

Astigmatism is usually found in the eyes during a comprehensive dilated eye exam. Being aware of any changes in your vision is important. It can help in detecting any common vision problems. If you notice any changes in your vision, visit your eye care professional for a comprehensive eye dilated examination.

Can you have astigmatism and not know it?

It is possible to have mild astigmatism and not know about it. This is especially true for children, who are not aware of their vision being other than normal. Some adults may also have mild astigmatism without any symptoms. It's important to have comprehensive dilated eye exams to make sure you are seeing your best.