An optometrist assesses a 60-year-old patient struggling to read small print despite using reading glasses. Why does the crystalline lens continue to lose accommodation amplitude with age?

💡 Explanation

The lens capsule's decreasing elasticity with age diminishes the lens's ability to alter shape during accommodation; this results in presbyopia. The capsular stiffening imposes a mechanical limit because the lens cannot respond to ciliary muscle contractions, therefore accommodation amplitude decreases rather than any change in the refractive index or muscle force.

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