Astigmatism

Astigmatism (also called astigmatism or irregular cornea) occurs when the cornea has an uneven shape, causing distorted and blurred vision. Vision can be impaired at all distances (both near and far) with astigmatism.

Astigmatism is divided into regular and irregular types. In regular astigmatism, there are so-called focal lines that are perpendicular to each other. The diopters needed to correct this type of astigmatism can usually be determined quite well. In contrast, the focal lines in irregular astigmatism can be completely disorganized relative to each other. In severe cases, the focal lines may hardly be recognizable as such. The light is refracted by the cornea in various directions. This type of astigmatism can only be partially corrected with glasses and usually requires either the fitting of special contact lenses or a customized laser treatment on the cornea.

In most cases, astigmatism—also known as astigmatism or irregular curvature of the cornea—is hereditary. However, a frequently pressing upper eyelid on the cornea can also be a cause.

Yes, astigmatism can gradually worsen, potentially leading to vision impairment across the entire field of view.

To correct astigmatism, special eyeglass lenses or contact lenses are commonly used. In some cases, the vision impairment can also be corrected surgically through laser therapy or by implanting so-called toric intraocular lenses.

Astigmatism often occurs together with nearsightedness (myopia) or farsightedness (hyperopia). However, both types of refractive errors are not directly related. Astigmatism is caused by an irregular curvature of the cornea, whereas nearsightedness or farsightedness result from a deformation of the eyeball. Therefore, all vision errors can also occur independently of each other.