Astigmatism is a type of refractive error in which the eye cannot focus light evenly on the retina
. This causes distorted or blurred vision at all distances. Other symptoms can include eyestrain
, and trouble driving at night
of astigmatism is unclear
. It is believed to be partly related to genetic factors. It can be diagnosed by eye exam
There are three
Types of astigmatism
Divided by the surface of the cornea
- Glasses are the simplest.
- Contact lenses can provide a wider field of vision.
- Refractive surgery will change the shape of the eye permanently.
Divided by the focus of images
- Regular astigmatism
- Irregular astigmatism
- Simple hyperopic astigmatism
- Simple myopic astigmatism
- Compound hyperopic astigmatism
- Compound myopic astigmatism
Keywords: astigmatism; hyperopic astigmatism; myopic astigmatism.