CONTRAST SENSITIVITY IN ONE-EYED SUBJECTS

The effects of early monocular form deprivation on the developing mamm alian visual system, and the anatomical and physiological consequences of early monocular enucleation, suggest that the remaining eye of hum an subjects who had the other eye removed early during development mig ht be capable of supernormal performance. To test this inference, the achromatic contrast sensitivity of the remaining eye of subjects who h ad the other eye removed at different ages after birth was compared wi th that of normal subjects tested under monocular and binocular condit ions. The results show that all subjects who had an eye removed during early development had a higher contrast sensitivity than the better e ye of control subjects. Furthermore, the earlier in development that t he eye was removed, the lower the spatial frequency at which contrast sensitivity is enhanced compared with measurements made in the better eye of control subjects, and the larger the range of spatial frequenci es over which contrast sensitivity is supernormal.