Tonic accommodation in young adults is approximately what diopter value, and how does it change with age?

Tonic accommodation in young adults is approximately what diopter value, and how does it change with age?

• A. Approximately 1.00 D and decreases with age
• B. Approximately 2.50 D and increases with age
• C. Approximately 0.25 D and remains constant
• D. Approximately 1.50 D and increases with age

Answer: (A)

Tonic accommodation is the small, baseline amount of accommodation the eye maintains when the lens is in a relaxed state, such as when looking at distant targets, reflecting the parasympathetic tone of the ciliary muscle. In young adults, this baseline is about 1.0 diopter. As people age, the accommodative system becomes less flexible (presbyopia), so this tonic accommodation decreases with age. Higher values or an increasing trend with age don’t fit the known pattern of age-related decline, and a very small constant value would ignore this aging effect.

Tonic accommodation is the small, baseline amount of accommodation the eye maintains when the lens is in a relaxed state, such as when looking at distant targets, reflecting the parasympathetic tone of the ciliary muscle. In young adults, this baseline is about 1.0 diopter. As people age, the accommodative system becomes less flexible (presbyopia), so this tonic accommodation decreases with age. Higher values or an increasing trend with age don’t fit the known pattern of age-related decline, and a very small constant value would ignore this aging effect.