Astigmatism: Symptoms, Causes & Treatment

Astigmatism is a very common refractive error resulting from an irregular shape of the cornea (the transparent front layer of the eye) or sometimes the inner lens. In a healthy eye the cornea is regularly spherical like the surface of a soccer ball, while in astigmatism it is closer to the oval shape of an American football, so light refracts unevenly and focuses at more than one point instead of a single point on the retina.

As a result, vision becomes blurry, distorted, or stretched at all distances, near and far, to varying degrees. Astigmatism often accompanies myopia or hyperopia in the same eye. It is a very common condition, may be present from birth, and may change over time, and is not linked to eye strain or reading in dim light as is commonly believed.

Astigmatism symptoms include blurry and distorted vision, eye strain, headache, the need to squint, and difficulty with night vision and glare around lights. It is not serious and is easily corrected. Correction relies on prescription glasses with cylindrical lenses, contact lenses (including rigid ones for some cases), or laser vision-correction surgery for suitable adults. Regular eye examination, especially for children, is important to detect and correct it to avoid its effect on performance and vision clarity.

• Blurry or distorted vision at all distances.
• Eye strain and the need to squint.
• Headache.
• Difficulty with night vision and glare around lights.

• Irregular curvature of the cornea (most common).
• Irregular shape of the inner lens.
• Genetic factors, and it may be present from birth.
• Sometimes after an eye injury or surgery or in keratoconus.

• Visual-acuity testing and refraction measurement.
• Corneal topography in some cases.
• A full eye examination by an ophthalmologist.

Vision correction

• Prescription glasses with cylindrical lenses.
• Contact lenses (including rigid ones for some cases).

Surgery

• Laser vision-correction surgery for suitable adults after the prescription stabilizes.

This content is educational and does not replace consulting an eye doctor.

• Eye strain and headache when uncorrected.
• Affected vision clarity and performance in children.
• Amblyopia (lazy eye) in severe untreated cases in children.

• There is no prevention, but early detection ensures proper correction.
• Regular eye examination, especially for children.
• Monitoring the change in prescription over time.