In astigmatism, the refractive power of the eye is not the same in all meridians, so it is not possible to concentrate the rays entering the eye at one point. In most cases, astigmatism is due to a corneal disorder.
In astigmatism both distant and near objects appear distorted.
This is because the curvature of the cornea is not uniform across its surface, so that light rays are not focused at the same level.
The diagnosis of astigmatism is made by:
- a simple measurement of a person’s visual acuity
- corneal topography (pentacam, topolyzer)
- Glasses with cylindrical lenses
- Toric contact lenses
- Refractive surgery with LASER