Answer: Surgical Vision CorrectionLight that enters your

Chapter 19, Problem 61PP

(choose chapter or problem)

 Problem 61PP

 

Surgical Vision Correction

Light that enters your eyes is focused to form an image on your retina. The optics of your visual system have a total refractive power of about +60 D—about +20 D from the lens in your eye and +40 D from the curved shape of your cornea. Surgical procedures to correct vision generally do not work on the lens; they work to reshape the cornea. In the most common procedure, a laser is used to remove tissue from the center of the cornea, reducing its curvature. This change in shape can correct certain kinds of vision problems.

The length of your eye decreases slightly as you age, making the lens a bit closer to the retina. Suppose a man had his vision surgically corrected at age 30. At age 70, once his eyes had decreased slightly in length, he would be

A. Nearsighted.

B. Farsighted.

C. Neither nearsighted nor farsighted.