Dark adaptation as a function of age : individual prediction.

Dark-adaptation thresholds were measured for 241 male subjects who ranged in age from 16 through 89 years. A multiple correlation of 0.91 was obtained between threshold sensitivity at the 40th minute (the criterion) and age combined with dark-adaptation thresholds taken at intervals of one minute for the first 10 minutes. A correlation of this magnitude allows the application of the regression equation to individual performance for the accurate prediction of terminal levels of dark-adaptation sensitivity.