How is astigmatism diagnosed?

How is astigmatism diagnosed?

An optometrist or ophthalmologist performs a complete eye exam to diagnose the problem.

Various tests measure how your eyes focus light and what type of lenses you need to improve your vision. Astigmatism tests include:

• Visual acuity: You read letters on a distance chart and receive a measurement (for example, 20/20 or 20/40). Alternative methods are used for young children and non-verbal patients.
• Keratometry/topography: This instrument measures the curve of your cornea. Your provider focuses light on the cornea and measures its reflection. This number is important for getting contact lenses that fit correctly and diagnosing regular versus disease-induced astigmatism.
• Refraction: Your provider measures how light focuses within your eye to create a clear or blurry image. This can be done with or without your input, so it can still be done in children and non-verbal adults.