Which condition is characterized by a decrease in visual clarity usually associated with aging?

The condition characterized by a decrease in visual clarity usually associated with aging is cataracts. Cataracts occur when the lens of the eye becomes cloudy, leading to blurred vision and decreased visual acuity. This process is often gradual, and while cataracts can occur at any age, they are most commonly associated with older adults. The clouding of the lens interferes with light passing through to the retina, which results in reduced clarity and can affect one’s ability to see clearly, especially in low-light conditions or at night.

Other options such as glaucoma are related to increased pressure in the eye and can lead to vision loss, but they are not primarily characterized by a decrease in clarity due to lens opacification. Diplopia refers to double vision, which is not directly linked to aging-related changes in clarity. Color blindness, on the other hand, involves difficulties in distinguishing colors and is typically a hereditary condition rather than one that develops with age.