Which is the minimum Hofstetter formula for near accommodative amplitude in terms of age?

Which is the minimum Hofstetter formula for near accommodative amplitude in terms of age?

• A. 15 - 0.25 x age
• B. 18 - 0.33 x age
• C. 12 - 0.5 x age
• D. 20 - 0.3 x age

Answer: (A)

Accommodative ability declines with age, and Hofstetter’s formulas give practical estimates for near focus capacity at any age. For the minimum near accommodative amplitude, the established formula is AA_min = 15 − 0.25 × age (in diopters). This sets the lower bound you’d expect for a healthy eye performing near tasks; values below can indicate accommodative insufficiency, while values above are more than sufficient for typical near work. For example, at age 25 the minimum predicted amplitude is 15 − 0.25×25 = 8.75 D; at age 40 it becomes 15 − 0.25×40 = 5 D. The other common Hofstetter estimates use different intercepts or slopes (mean or maximum), but the question asks for the minimum, which matches the 15 − 0.25 × age formula.

Accommodative ability declines with age, and Hofstetter’s formulas give practical estimates for near focus capacity at any age. For the minimum near accommodative amplitude, the established formula is AA_min = 15 − 0.25 × age (in diopters). This sets the lower bound you’d expect for a healthy eye performing near tasks; values below can indicate accommodative insufficiency, while values above are more than sufficient for typical near work.

For example, at age 25 the minimum predicted amplitude is 15 − 0.25×25 = 8.75 D; at age 40 it becomes 15 − 0.25×40 = 5 D. The other common Hofstetter estimates use different intercepts or slopes (mean or maximum), but the question asks for the minimum, which matches the 15 − 0.25 × age formula.