Development of a Device to Measure the Degree of Visual Distortion Encountered in Underwater Diving

Abstract

A simulated underwater visual diving situation was constructed on dry land that would eliminate feedback,.as much as possible, from the proprioceptive and motor response systems. The constructed simulated diving environment permitted strict control of the visual field so that only one type of underwater “pincushion” distortion was observed by the experimental group. Additional phases of construction included the development of a mechanism that would permit adjustment of curvature in a horizontal straigtht line and the development of a measurement stand that would permit accurate measurements of degree of line curvature adjustment. After rigorous visual screening subjects were assigned at random to an experimental and control group. Pre- and posttreatment measurements were taken on both groups. The experimental group observed “pincushion” distortion in a viewing tank for 30 min. The control group observed a flat surface in the same tank for the same time span. Results indicated that both groups improved in degree of adaptation to visual distortion with the experimental group experiencing the greatest adaptation. Evidence indicates that the visual system is a primary site of adaptation to visual distortion.