Astigmatism is a disorder of vision, a very common optical problem.
Astigmatism can appear at any time in life. It is due to anomalies specific to the eye that are called the lenses of the eye: the cornea, the lens. These lenses create a sharp image focused on the retina. If one of the lenses is of poor quality, the image will be blurred.
The astigmatism does not see well, near or far. Astigmatism is an abnormality of vision characterized by a bad curvature of the cornea (transparent membrane that covers the eye at the level of the iris); it is oval instead of round. The deformation can be vertical, horizontal or oblique. The same problem can affect the lens of the eye that is the lens.
Astigmatism can be congenital or acquired (that is, it appears after birth, often in adolescence or adulthood).
Astigmatism causes a blurred vision from near and far, the anomaly is more or less important depending on the deformation. An astigmatic person may also be nearsighted or hyperopic. In this case, the correction requires to take care of all these disorders. This is easily done today with the ophthalmologist, then with the optician when getting his glasses or his lenses.
Astigmatism is measured, measured in diopter, as myopia or hyperopia.