A person uses about what percentage of their accommodation ability comfortably?

A person uses about what percentage of their accommodation ability comfortably?

• A. 25 percent
• B. 50 percent
• C. 75 percent
• D. 100 percent

Answer: (B)

The key idea is that you don’t need to, and shouldn’t, use all of your accommodative power for comfortable viewing. The eye has a total accommodative amplitude—the maximum diopters it can achieve when focusing from distance to near. For sustained, comfortable near work, you typically use about half of that available capacity. That leaves a reserve for small focus adjustments and helps prevent fatigue or asthenopia. So, for most people, about 50 percent of their accommodation ability is used comfortably.

The key idea is that you don’t need to, and shouldn’t, use all of your accommodative power for comfortable viewing. The eye has a total accommodative amplitude—the maximum diopters it can achieve when focusing from distance to near. For sustained, comfortable near work, you typically use about half of that available capacity. That leaves a reserve for small focus adjustments and helps prevent fatigue or asthenopia. So, for most people, about 50 percent of their accommodation ability is used comfortably.