MEDizzy - A 25-year-old student with 20/20 vision looks up from his

Feed Library Learning Discuss Leaderboard Journal

The Nervous System (The Special Senses)

A 25-year-old student with 20/20 vision looks up from his book to view his girlfriend sitting on the other side of the room. Which of the following is most likely to occur when the student changes his view from his book to his girlfriend?

ExplanationLight rays from distant objects do not require as much refraction (bending) as do light rays from objects close at hand. Therefore, a thinner lens with less curvature is required for viewing distant objects. The process of accommodation adjusts the thickness of the lens for near and far vision by contracting or relaxing the ciliary muscle that surrounds the lens of the eye; contraction of the ciliary muscle thickens the lens, and relaxation causes the lens to become thinner.