What eye disorder is characterized by distorted and blurry vision due to irregular curvature of the cornea or lens?

Astigmatism is characterized by distorted and blurry vision that arises from an irregular curvature of the cornea or lens. In a healthy eye, the cornea and lens are smoothly curved, allowing light to focus properly on the retina. However, in individuals with astigmatism, the cornea or lens has a more oblong shape, causing incoming light to be focused on multiple points rather than a single point on the retina. This leads to the blurriness and distortion that patients experience, making it difficult to see fine details clearly.

Myopia (nearsightedness), hyperopia (farsightedness), and presbyopia (age-related difficulty in focusing on close objects) are distinct refractive errors that involve focusing issues due to either the length of the eyeball or age-related changes in lens flexibility, rather than the shape irregularities associated with astigmatism. Thus, the specific nature of astigmatism—centered around the structural shape of the eye—distinguishes it from these other visual disorders.