Where is the far point of an emmetropic eye located?

Where is the far point of an emmetropic eye located?

• A. Optical infinity
• B. In front of the retina
• C. Behind the retina
• D. At the corneal plane

Answer: (A)

In an emmetropic eye, the optical power and the length of the eye are matched so that light from distant objects (parallel rays) is focused exactly on the retina without needing any accommodation. That means the far point—the point in space from which rays entering the eye can be focused on the retina with the eye in its relaxed state—lies at optical infinity. The other options would imply refractive errors: in front of the retina suggests myopia, behind the retina suggests hyperopia, and the corneal plane is not the defining location of the far point. So optical infinity is the correct location.

In an emmetropic eye, the optical power and the length of the eye are matched so that light from distant objects (parallel rays) is focused exactly on the retina without needing any accommodation. That means the far point—the point in space from which rays entering the eye can be focused on the retina with the eye in its relaxed state—lies at optical infinity. The other options would imply refractive errors: in front of the retina suggests myopia, behind the retina suggests hyperopia, and the corneal plane is not the defining location of the far point. So optical infinity is the correct location.