Describe the relationship of the crystalline lens' ability to accommodate to aging.

• A. The amplitude of accommodation increases with age.
• B. The amplitude of accommodation remains constant after adolescence.
• C. The amplitude of accommodation decreases with age.
• D. Accommodation becomes faster with age.

Answer: (C)

As people age, the lens loses its elasticity and becomes stiffer. Accommodation—the ability to increase the lens’s curvature to see near objects clearly—depends on the lens being flexible enough to change shape when the ciliary muscle contracts. When the lens hardens and the zonules become less compliant, it can’t change shape as much, so the dioptric power you can achieve for near vision drops. This gradual loss of focusing ability is what we call presbyopia, and it means the amplitude of accommodation decreases with age—from a high range in youth to very little by older adulthood.

If you think about it in terms of distance focus, the far point stays relatively stable, but the near point moves farther away as age increases, reducing the overall accommodating range. This decline is why middle-aged adults often need reading glasses or other near-vision corrections.

So the correct idea is that the amplitude of accommodation decreases with age. The other notions—that it increases, stays constant after adolescence, or that accommodation becomes faster with age—don’t match how the eye’s lens changes over time.