Procedural Effects on the Manifest Human Amplitude to Accommodation

Numerous investigators since Donders in 1864 have published data on the ocular amplitude of accommodation. In most of these investigations, however, only one set of experimental conditions was used. In this investigation, I used various sets, each of which was presented to 55 males and 55 females from age 13 through age 67. The major results of this investigation were: a) The tables attributed to Donders do not agree with his raw data. b) Subjective grasping of the target stage manifested statistically higher amplitudes than when it was not grasped. c) Movement of the target towards the subject manifested statistically higher amplitudes than when the target was moved away from him. d) Statistically higher amplitudes were manifested for binocularity than monocularity above age 32, but not at younger ages. e) There was no statistical significance between the amplitudes of males and females of the same age group.