Adaptation of Divers to Size Distortion Under Water

A diver's face‐mask produces an optical distortion of the relationship between size and distance under water, with the result that objects normally appear further than the optical distance and enlarged. Adaptation to size enlargement was examined by obtaining size estimates in air and water, before and after a period of 20–40 min. underwater activity in which objects of known size were handled. Size estimates were obtained by adjusting a line to an estimated length of 12 in. Initial estimates in water indicated that novices experienced more size enlargement than experienced divers. Both groups of divers showed significant aftereffects in air, indicating that some size adaptation had occurred. The aftereffect declined rapidly, and was significant for only the first two trials. A second experiment showed that the greater accuracy of experienced divers also occurred when looking into water through a porthole: it was not, therefore, ‘situation‐contingent’ in the sense that it depended upon wearing a face‐mask in water

Adaptation (eye) · Apparent Size · Audiology · Cognitive psychology · Distortion (music) · Face (sociological concept) · Geography · Geometry · Line (geometry) · Statistics · Telecommunications · Underwater · Computer Science · Mathematics · Psychology · Visual perception and processing mechanisms