# Astigmatism

URL: https://mohamedmohyudin.co.uk/conditions/astigmatism/
Last reviewed: 2026-08-13

## Quick answer

Astigmatism is a common refractive error in which the cornea or lens is not perfectly spherical, shaped more like a rugby ball than a football. This causes light to focus at two different points rather than one, producing blurred or distorted vision at all distances. Most cases are mild and easily corrected.

## Overview

Astigmatism is one of the most common refractive errors, affecting an estimated 30–40% of adults to some degree. It occurs when the cornea or lens is not perfectly spherical — instead of being round like a football, it is shaped more like a rugby ball. This causes light to focus at two different points rather than one, producing blurred or distorted vision at all distances. Most cases of astigmatism are mild and easily corrected.

## Treatment

Mild astigmatism may need no treatment. Spectacles or toric contact lenses correct the irregular focus. Toric intraocular lenses (IOLs) at the time of cataract surgery can address pre-existing astigmatism. Laser vision correction (LASIK, LASEK) reshapes the cornea.

## FAQs

### What are the symptoms of astigmatism?

Astigmatism causes blurred or distorted vision at all distances. Other symptoms include eye strain and headaches, particularly after prolonged reading or screen use, squinting to see more clearly, difficulty with night vision such as halos around lights, and asthenopia (eye fatigue). Most cases are mild and easily corrected.

### What causes astigmatism?

Astigmatism most commonly results from an irregular curvature of the cornea (corneal astigmatism). It can also arise from an irregular curvature of the crystalline lens (lenticular astigmatism), corneal scarring following injury or infection, or keratoconus, a progressive thinning of the cornea. The cornea or lens is not perfectly spherical.

### How is astigmatism treated?

Mild astigmatism may need no treatment. Spectacles or toric contact lenses correct the irregular focus. Toric intraocular lenses (IOLs) fitted at the time of cataract surgery can address pre-existing astigmatism. Laser vision correction, such as LASIK or LASEK, reshapes the cornea to correct the irregular focus.