What is Astigmatism?

Astigmatism is a common focusing disorder caused by an irregular shape of the cornea or lens. Most commonly, the front of the eye is not perfectly round or spherical, causing light entering the eye to focus on multiple points, resulting in blurred or distorted vision.

Diagram illustrating astigmatism

Signs and Symptoms

Blurred or Distorted Vision

Vision may appear wavy, blurry, or 'stretched' in a specific way as light rays are being focused unevenly on the retina (back of the eye).

Eyestrain from screens

Eye Strain

Astigmatism often causes visual fatigue and discomfort, especially after reading or screen use for long periods.

Headaches and visual strain

Headaches

Uncorrected astigmatism can lead to frequent headaches due to the constant effort needed to focus vision.

Night glare icon

Glare and Halos at Night

Astigmatism can make bright lights appear scattered or cause halos, especially during nighttime driving or looking up at the stars.

Detection and Diagnosis

Astigmatism is diagnosed during a comprehensive eye examination. Vision care specialists, such as optometrists, typically use tools like a phoropter and retinoscope to measure the amount and type of astigmatism. Other specialized equipment, such as corneal topography, is used to map the front of the eye to monitor for underlying eye diseases resulting in astigmatism.

Did you know? Most people have a small amount of astigmatism — even if their vision seems clear!

Treatment Options

Astigmatism is typically corrected with prescription glasses or toric contact lenses that compensate for the two different focuses within the eye. Frequent and erratic changes in astigmatism can often be a sign of an underlying disease, like keratoconus or other eye health problems.

In advanced cases where astigmatism becomes irregular, a specialized optometrist will need to fit hard and scleral contact lenses to improve vision.

Managing Astigmatism

Early detection ensures optimal correction and comfort. It is especially important in children, where uncorrected astigmatism may affect learning and development. Regular eye exams help keep prescriptions up to date and detect any vision changes timeously.