**Question:** Accommodation is maximum at the age of

A. 20 years
B. 40 years
C. 45 years
D. 60 years

**Correct Answer:** D. 60 years

**Core Concept:** Accommodation is the process by which the ciliary muscle contracts, causing the crystalline lens to change shape, allowing for focusing on nearby objects. This process decreases in efficiency with age, contributing to presbyopia.

**Why the Correct Answer is Right:** Accommodation is known to decline gradually with age, which is why it is at its maximum efficiency around the age of 60 years. In this age group, the ciliary muscle contractions and lens shape changes are most effective for focusing on nearby objects.

**Why Each Wrong Option is Incorrect:**

A. 20 years: Accommodation is not at its peak efficiency at this young age, as the ciliary muscle and lens shape changes have not yet fully developed.
B. 40 years: While accommodation may decrease slightly in this age range, it is not at its maximum efficiency compared to the peak efficiency at 60 years.
C. 45 years: Accommodation efficiency continues to decline gradually after 40 years, but it is not at its maximum at 45 years.

**Clinical Pearl:** Presbyopia is a common age-related refractive error that occurs due to the gradual loss of lens flexibility and accommodation efficiency. Understanding the age-related changes in accommodation is essential for managing presbyopia and prescribing appropriate corrective lenses.