CHARACTERISTICS OF DYNAMIC ACCOMMODATION RESPONSES - COMPARISON BETWEEN THE DOMINANT AND NONDOMINANT EYES

Accommodation responses of dominant and non-dominant eyes were compare d in 18 healthy subjects aged 19-21 years to clarify the characteristi cs of dynamic accommodation. Internal targets were placed at -0.25 D a nd -4.0 D in an infrared optometer of a modified model, and external t argets (brightness 30 cd/cm(2) diameter 35 mm) identical in appearance with the internal targets, were placed 4.0 m and 0.25 m in front of t he eyes. Three experiments were carried out by monocular viewing of th e internal targets and monocular and binocular viewing of the external targets, and the results were compared between the dominant and non-d ominant eyes. In viewing the internal targets, near-to-far responses w ere suppressed. In binocular viewing, the accuracy of accommodative po sition was increased, and the function of dynamic responses was improv ed. Furthermore, myopic shifts were observed in the near position afte r far-to-near accommodation and in the far position after near-to-far accommodation in the dominant eye compared with the non-dominant eye, and shortening of the response time and an increase in the response ve locity were noted only in binocular viewing. These findings suggest th at the dominant eye is in a tonic state and plays the primary role in far-to-near accommodation in binocular viewing. Copyright (C) 1996 The College of Optometrists.