Well, in a perfectly-shaped eye, the cornea, or surface layer, is a sphere, like a baseball. It allows light to enter your eyes at the right angle and focus just so on the retina. That means your vision is sharp and crisp. But with astigmatism, the cornea's shape is more like a football than a baseball. This irregularity makes the light rays focus on two points on the retina, not one. This causes blurry, distorted vision.
Simply put, astigmatism is a condition derived from a cornea or lens that's stretched into an irregular shape. Instead of being shaped round, the corneas of people with astigmatism are often oblong. This causes a refractive error, distorting light as it enters your eyes. As a result, images appear blurry.
Astigmatism is an eye condition with blurred vision as its main symptom. The front surface of the eye (cornea) of a person with astigmatism is not curved properly-the curve is irregular-usually one half is flatter than the other-sometimes one area is steeper than it should be. When light rays enter the eye they do not focus correctly on the retina, resulting in a blurred image. Astigmatism may also be caused by an irregularly shaped lens, which is located behind the cornea. Astigmatism may occur in children and adults; it is fairly common and is not contagious. It is usually congenital-is present at birth-but can develop after an eye operation or an injury to the eye. It belongs to a group of eye conditions called refractive errors. Myopia (short-sightedness), hypermetropia (long-sightedness) and presbyopia (aging of the lens in the eye) are types of refractive errors. A refractive error means that the shape of the eye does not bend light properly, resulting in a blurred image. Light has to be bent (refracted) by the lens and the cornea correctly before it reaches the retina in order to see things clearly.