Causes And Diagnoses
Causes and Diagnoses of Astigmatism
When light enters your eye, it is refracted (bent) by the cornea and lens to create a sharp image on your retina. When your cornea and lens aren’t perfectly round, or are curved more steeply in one direction, the light isn’t focused evenly on the retina.
Generally, astigmatism is congenital, or present at birth. Other causes can include:
- Injury to the eye
- Eye surgery
Your physician can identify astigmatism in a comprehensive eye exam. Any one of the following exams can determine if the curvature of your cornea and lens is impacting your vision:
- Visual acuity test: This common eye chart test measures vision ability at various distances using a series of lenses.
- Pupil dilation: The pupil is widened with eyedrops to allow a close-up examination of the eye's lens and retina.
- Keratometer: This device measures the curvature of surface of your cornea.
- Corneal topography (photokeratoscopy): This imaging test maps the curvature of your cornea.