1994 年 12 巻 2 号 p. 85-97
The characteristics of the visual and tactual activities were investigated in a congenitally blind person before and soon after an operation performed for regaining his sight. The subject was born blind due to congenital cataracts, and underwent aspiration of both cataractous lenses at the age of 9. Before the operation, his ERG was normal. After the operation he wore +12D lenses. The results obtained were as follows: (1) Before the operation, he could identify colors. To some extent, he could also count objects, discriminate the size of 2 two-dimensional rectangles or two circles. On the other hand, he could not identify two-dimensional figures. (2) During the 15 days after the second eye operation, his percentage of correct responses increased in all tasks, except for discrimination of the size of 2 two-dimensional circles. (3) Postoperatively, the patient no loger attempted to touch objects after counting them and discriminating the size of 2 two-dimensional rectangles, but with either size discrimination of the circular shapes or identification of shapes, he touched them after looking at them, just as before the operation.