Which eye condition is characterized by a decrease in visual acuity due to clouding of the lens?

The condition characterized by a decrease in visual acuity due to clouding of the lens is cataract. Cataracts develop when proteins in the lens of the eye clump together, leading to a cloudy appearance that interferes with light passing through the lens. This clouding can result in blurred vision, increased glare from lights, and difficulty seeing at night, ultimately affecting overall visual acuity.

Cataracts commonly occur with aging, but can also result from other factors such as prolonged exposure to UV rays, smoking, and certain medical conditions. The only effective treatment for cataracts is surgical removal of the cloudy lens, which is often replaced with an artificial intraocular lens.

Retinopathy refers to damage to the retina, often caused by conditions like diabetes, affecting sight but not related to the lens specifically. Amblyopia, or "lazy eye," is a developmental issue that affects vision in one eye and is not caused by lens clouding. Astigmatism is a refractive error, typically resulting from an irregular curvature of the cornea or lens, and affects how light is focused in the eye rather than causing cloudiness in the lens itself.