Which condition is characterized by double vision?

The condition characterized by double vision is known as diplopia. This occurs when a person perceives two images of a single object, which can happen for various reasons, such as misalignment of the eyes, issues with the eye muscles, or problems with the nerves controlling the eye muscles. Diplopia can be temporary or chronic and may occur in one eye (monocular diplopia) or both eyes (binocular diplopia).

Understanding the difference in terminology provides context for the other options. Astigmatism refers to a refractive error in the eyes that causes blurred vision due to an irregular shape of the cornea or lens. Strabismus involves the misalignment of the eyes, where one eye may look straight ahead while the other turns in different directions. Ambliopia, often referred to as "lazy eye," is a condition where one eye has reduced vision often due to a developmental issue. While strabismus may lead to diplopia in some cases, the term diplopia specifically denotes the experience of seeing double, making it the correct answer.