Astigmatism is a common, mild and easily treatable imperfection in the curvature of your eye. The condition can cause blurred vision. Astigmatism occurs when the front surface of your eye (cornea) or the lens, inside your eye, has a slightly different surface curvature in one direction from the other. Instead of being even and smooth in all directions, the surface may have some areas that are flatter or steeper.

Astigmatism blurs your vision at all distances. Astigmatism is often present at birth and may occur in combination with nearsightedness or farsightedness. Often it's not pronounced enough to require corrective action. When it is, your treatment options include corrective lenses and surgery.

Symptoms

Signs and symptoms of astigmatism may include:

• Distortion in portions of your visual field

• Blurred vision

• Eyestrain

• Headaches.

Astigmatism may occur in combination with other refractive errors, which include:

• Nearsightedness (myopia). This occurs when your cornea is curved too much or your eye is longer than normal. Instead of being focused precisely on your retina, light is focused in front of your retina, resulting in a blurry appearance for distant objects.

• Farsightedness (hyperopia). This occurs when your cornea is curved too little or your eye is shorter than normal. The effect is the opposite of nearsightedness. When your eye is in a relaxed state, light is focused behind the back of your eye, making nearby objects blurry.

Tests and diagnosis

Keratometer. This instrument quantifies the amount and orientation of corneal astigmatism by measuring reflected light from the surface of your cornea.

Keratoscope and videokeratoscope. These devices are used to detect and quantify corneal surface curvature and the presence of astigmatism.

Treatment:

Corrective lens either by using spectacles or contact lens.

Refractive surgery:

• Laser-assisted in-situ keratomileusis (LASIK).

• Laser-assisted subepithelial keratomileusis (LASEK).

• Photorefractive keratectomy (PRK).

• Anterior chamber intraocular lens (IOL) implant.