Accommodative response during distance optometric test procedures.

The control of accommodation is an essential requirement during the clinical optometric assessment of distance vision. Accordingly, the aim of the present study was to examine the steady-state accommodative response during a number of conventional clinical procedures carried out at a viewing distance of 6m (20 feet). Accommodation was measured subjectively to Snellen letters using a Hartinger coincidence optometer during distance viewing, simulated retinoscopy and following the introduction of cylindrical and prismatic lenses in 13 visually-normal, young adults. No significant change in the mean accommodative response was induced by any of the techniques described, with subjects exhibiting a lead of accommodation of approximately 0.25D for all conditions. The results demonstrate the robustness of accommodation to apparently substantial changes in stimulus conditions.