Astigmatism is a common visual disorder. Astigmatism is caused by the irregular shape of the eye affecting the way that light rays are focused, resulting in distorted vision. However, this visual defect is treatable.

Astigmatism is caused by the eye not being regular or spherical in its shape. In a person without astigmatism, the cornea is a regular sphere, like a football. In a person with astigmatism, however, the eye is not totally spherical, and is shaped more like a rugby ball or an egg, which has a steep and flat axis in its shape.

This means the refractive components of the eye (the parts that focus light) do not allow the light rays to meet in the correct place. The result is blurred or distorted vision, where objects can appear blurred or elongated in a particular direction. In some patients, increasing astigmatism may be a sign of keratoconus.

Read more about keratoconus 

People with astigmatism suffer from blurred vision and/or eye strain.

Without optical correction, there is no way the optical system can compensate for the refractive error caused by an irregular shape of the eye. As a result, untreated sufferers of astigmatism can experience symptoms including:

• Blurred vision
  
• Eye strain
  
• Squinting or ‘screwing up’ of eyes
  
• Headaches
  
• Fatigue

Glasses, contact lenses and laser eye surgery are all appropriate methods of treatment. Astigmatism can also be corrected at the time of cataract surgery with an appropriate toric lens implant.

Read more about cataract surgery at Forest Eye Surgery