[Physiological specificity of dark focus of accommodation].

There is a controversy concerning the difference between the resting state of accommodation in the dark-(dark focus of accommodation) and that in the light field (empty field). Previous investigations have reported individual differences in resting points, too. In this study, 113 subjects the resting state in the dark- and light-field were measured. It was found that aging and refractive powers cause remarkable changes of the resting state, and the resting state was more myopic in the light field than in the dark field, but the resting state in the light approached the far point in the forties and the state was almost same in the dark- and light field. The results show the resting state may not be identical for all subjects.