Astigmatism is an eye condition wherein there is an abnormality in the curvature of the eye surface or cornea. People with astigmatism have blurred vision, and their ability to focus on objects is impaired. Astigmatism is usually accompanied by nearsightedness or farsightedness. The anomaly in the curvature causes light that comes in to not focus directly on the retina, making it blurred. Sometimes, a person with astigmatism might have an abnormally shaped lens, which is located behind the cornea, and this is properly termed as lenticular astigmatism versus corneal astigmatism.

Astigmatism is very common and is easily treatable. Astigmatism is usually present at birth, while some people develop it after some kind of trauma to the eye. Lenticular astigmatism usually affects people with diabetes, because high sugar in the blood tends to change the shape of the lens in the eye.

In many cases an ophthalmologist will prescribe corrective lenses such as eyeglasses or a pair of contact lenses. Young children will usually be prescribed glasses as opposed to contacts because of the care and dexterity required to maintain and use contacts.

In some cases, photorefractive keratectomy (PRK) is performed where the cornea is evened out through the removal of tissue. Laser epithelial keratomileusis (LASEK) can also be performed, which is a bit less painful that PRK. In this case alcohol is applied to the cornea, after which it is removed, then a laser reshapes the it before being put back in the eye.  Laser in situ keratectomy is arguably the most famous treatment, also known as LASIK. Here, the cornea is cut to form a flap which the doctor can reshape, to be put back in place after the reshaping is done.