The normal cornea is curved like a hemisphere, which means that incoming light is evenly focused on a point. However, if the cornea is curved like an ellipse, the light rays are not focused on a point but on a line. As a result, the image is distorted and perceived with double contours.
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A so-called cylindrical lens can compensate for corneal curvature.
example:
Alternatively, soft or hard contact lenses can also be adjusted.
Corneal curvature up to -4 diopters can be caused by eye laser be permanently corrected. To correct major curvatures, PIOLs (phake intraocular lenses) can be implanted.
The astigmatism of the cornea is inherited in the vast majority of cases and remains stable throughout life. If there is an increase in astigmatism, corneal diseases (e.g. keratoconus/Pellucide marginal degeneration) can be excluded. With a Crosslinkig treatment Can these corneal diseases be stabilized. In these cases, it is generally not recommended for the time being before a classic laser eye procedure.