Astigmatism Test

Check for signs of astigmatism with a starburst pattern and clock dial test. Quick, free, and private.

Sit about 35 cm (14 inches) from your screen. If you wear glasses, keep them on. Cover one eye and look at the center of the pattern below.
Do all lines appear equally dark, sharp, and evenly spaced?
Which eye are you testing?
Look at the clock face below with one eye covered. Do all the lines between the numbers appear equally bold and sharp?
Which lines appear darker or bolder? (select one)
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What Is Astigmatism?

Astigmatism is a common vision condition caused by an irregular curvature of the cornea or lens. Instead of being perfectly round like a basketball, the eye is shaped more like a football, causing light to focus at multiple points rather than one. This results in blurred or distorted vision at all distances.

Symptoms of Astigmatism

Common symptoms include blurred or distorted vision, eye strain, headaches (especially after reading or screen use), difficulty seeing at night, and squinting. Mild astigmatism may cause no noticeable symptoms, while moderate to severe cases significantly affect daily activities like reading and driving.

How the Starburst Test Works

The starburst pattern shows lines radiating from a central point at equal intervals. If your cornea has a regular shape, all lines appear equally dark and sharp. If you have astigmatism, lines along one axis will appear darker or sharper than others because the eye focuses that axis more clearly.

How Astigmatism Is Corrected

Astigmatism is easily corrected with cylindrical lenses in glasses or toric contact lenses. These lenses compensate for the uneven curvature of the cornea. For a permanent solution, refractive surgery options like LASIK or PRK can reshape the cornea. An eye care professional will determine the best correction for your specific case.

Prevalence

Astigmatism is extremely common, affecting about one-third of the population. Most people have some degree of astigmatism. It can be present from birth or develop gradually. It often occurs alongside nearsightedness (myopia) or farsightedness (hyperopia).

When to See an Eye Doctor

If this test suggests astigmatism, or if you experience blurred vision, frequent headaches, or eye strain, schedule a comprehensive eye exam. An optometrist can precisely measure astigmatism with instruments like a keratometer and autorefractor, and prescribe the correct lenses.