Astigmatism is a refractive error caused by uneven curvature of the cornea or lens, so the eye focuses light at different points rather than a single sharp focus. It leads to blurred or distorted vision at all distances.
Characteristics
The cornea may be steeper in one meridian and flatter in another, similar to a rugby ball rather than a football. This irregularity can occur alone or alongside myopia or hyperopia.
- Measured as cylinder power and axis on a glasses prescription
- Even small amounts can cause eye strain or headaches
- Higher or irregular astigmatism may indicate conditions like keratoconus
Correction and Evaluation
Astigmatism is corrected with glasses, toric contact lenses, or refractive surgery. Corneal topography helps detect irregular forms and is routinely used in laser eye surgery planning at Blue Fin Vision®; their blog on the difference between long and short sight also touches on astigmatism.
Monitoring
Significant astigmatism in children should be monitored to prevent amblyopia and ensure good visual development.
