What condition is characterized by blurred and stretched vision due to uneven focus on the retina?

Astigmatism is a condition that causes blurred or distorted vision due to the irregular shape of the cornea or lens in the eye. In a healthy eye, light rays enter and are focused evenly on the retina, but in astigmatism, the uneven curvature of the cornea leads to multiple focus points instead of a single point on the retina. This irregular focus results in images appearing stretched or blurred, particularly when viewing objects at various distances.

The other conditions listed differ in their causes and effects on vision. For instance, cataracts typically cause clouding of the lens, leading to hazy or blurred vision but not specifically due to uneven focus on the retina. Glaucoma involves damage to the optic nerve, often associated with increased pressure in the eye, leading to vision loss rather than distortion from uneven focus. Myopia, or nearsightedness, results when distant objects appear blurry while close objects can be seen clearly, which is a different issue related to the eyeball's shape or refractive power rather than uneven curvature. Therefore, astigmatism specifically aligns with the characteristic of blurred and stretched vision due to uneven focus on the retina.