Fig. 3. Decrease in the amplitude of accommodation with age in the human. Open symbols, female; solid symbols, males. A. Left eye, based on subjectively reported clarity of target viewed through trial lenses of progressively decreasing plus or increasing minus power. B. Phenylephrine-dilated right eye, based on Hartinger coincidence refractometry while subject accommodated to view target with left eye, as in A. (Koretz JF, Kaufman PL, Neider MW et al: Accommodation and presbyopia in the human eye—aging of the anterior segment. Vis Res 29:1685, 1989)