ABSTRACT The convergent accommodation/convergence (CA/C) ratio was measured in 30 subjects comprising 10 late‐onset myopes (LOM's), i.e., myopia onset at 15 years of age or later, 10 early‐onset myopes (EOM's), and 10 emmetropes. The accommodation loop was opened by two methods: (1) the subject viewed a 0.1‐mm diameter spotlight at distances of 33 and 100 cm and (2) the subject viewed near‐type (viewing distance 33 cm) through 0.5‐mm pin‐holes. Convergence was stimulated by the introduction of 3 and 6 A base‐out prisms before the right eye and the accommodative response of the left eye was measured using an objective infrared optometer (Canon Autoref R‐1). There was no significant difference in CA/C between the three refractive groups with either method. The implications of this finding are discussed with reference to previous work on accommodative convergence/accommodation (AC/A) and disparity‐induced accommodation and in relation to accommodation‐vergence synkinesis in late‐onset myopia.
Rosenfield et al. (Tue,) studied this question.