Astigmatism (noun)

1. An eye condition in which the cornea or lens is irregularly shaped, causing distorted vision.
2. A condition that is caused by an irregular shape of the cornea or lens of the eye, resulting in distorted vision.

Origin:

From the greek word "stigma" meaning a mark or point, referring to the irregularity in the shape of the cornea or lens of the eye.

Examples:

1. He had an astigmatism in his left eye and had to wear glasses.
2. Astigmatism can cause blurred vision at all distances.
3. Astigmatism is a common refractive error of the eye.
4. He was diagnosed with astigmatism and needed to wear corrective lenses.
5. Astigmatism can be corrected by using glasses, contact lenses or refractive surgery.