Astigmatism is another term for which condition?

Astigmatism is a refractive error caused by an irregularly shaped cornea or lens, resulting in blurred or distorted vision. It occurs when the eye does not focus light evenly on the retina due to the curvature of the cornea or lens being uneven, leading to different focal points.

While myopia, or nearsightedness, and hyperopia, or farsightedness, are common refractive errors, they are distinct from astigmatism. Myopia typically occurs when the eyeball is too long or the cornea is too steep, causing distant objects to appear blurry. Presbyopia is related to age and affects the eye's ability to focus on close objects due to the hardening of the lens, which is also different from astigmatism.

Given this context, identifying astigmatism simply as another term for myopia is incorrect, as they describe different conditions. The term "none of the above" is actually the correct classification as it indicates that none of the provided options accurately defines astigmatism.