Astigmatism is a common eye condition that causes blurred or distorted vision. It occurs when the cornea (the clear front layer of the eye) or lens (an inner part of the eye that helps the eye focus) has a different shape than normal. Instead of having a round shape like a basketball, the surface of the cornea or lens is egg-shaped, which causes light rays to be bent differently as they enter the eye. This results in two different images forming, which overlap or combine and cause blurred vision at all distances. Astigmatism can occur at birth and may occur in combination with nearsightedness or farsightedness. Symptoms of astigmatism include blurry vision, needing to squint to see clearly, headaches, eye strain, and trouble seeing at night. Astigmatism can be diagnosed through a complete eye exam, and treatment options include corrective lenses or surgery.