Astigmatism: understanding and correcting it
Astigmatism causes blurred or doubled vision at every distance. It most often results from a cornea whose curvature is not perfectly spherical. It can be corrected effectively, whether on its own or combined with another refractive error.
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What is astigmatism?
A normal cornea is curved regularly, like a football. In astigmatism, it is a little more "oval", like a rugby ball: light is not focused at a single point, which makes vision blurred or distorted at both distance and near. It is often associated with myopia or hyperopia.
How is it corrected?
Regular astigmatism corrects very well with laser surgery: LASIK, PRK or SMILE (for myopic astigmatism). The laser reshapes the cornea to restore a regular curvature.
Astigmatism and lens surgery
When lens surgery is planned (cataract surgery or clear lens exchange), a toric implant can correct astigmatism at the same time.
Irregular astigmatism
Irregular or worsening astigmatism should prompt a search for corneal deformation, such as keratoconus. Corneal topography is essential before any correction.
Frequently asked questions
Can astigmatism be operated on its own?
Yes, astigmatism can be corrected with laser surgery, either on its own or at the same time as an associated myopia or hyperopia.
Can high astigmatism be operated?
Often yes, with laser surgery or a toric implant during lens surgery. The assessment identifies the best strategy based on the magnitude and regularity of the astigmatism.
Can astigmatism hide a corneal disease?
Irregular or evolving astigmatism can reveal keratoconus. This is why corneal topography is part of the systematic assessment.
Before you decide
All questions →Vision distorted by astigmatism?
A topographic assessment points to the most suitable correction.
Book an appointmentThis page is for general information purposes only and does not replace a medical consultation. The indication and technique are always individualised after a complete assessment. Prof. Eric E. Gabison — cornea and refractive surgery, Fondation Adolphe de Rothschild, Paris.