開眼手術後における視機能とその分化 : 視空間の構造を中心として

抄録

In order to clarify the characteristics of perception of visual space in the early or congenitally blind who have just gained sight after surgery, a series of experiments covering a period of over 10 years were conducted. Subject KT in this paper, who lost her sight binocularly due to congenital cataract, received the operation on her left eye at the age of 15. The following results were obtained: (1) The perceived size of an object placed at various distances on a table decreases when the physical distance exceeds 20cm approximately. The ratio of perceived sizes to physical distances demonstrates that the size constancy is not so high as that of the normally sighted adult. (2) Color perception was slightly easier than that of shape, but it became difficult when the observation distance (D) extended 60cm and when the size of color paper was small. (3) Identification of the shape of a figure was difficult when the figure was presented at D>35cm. At a near distance she could scan the shape as a whole, but at a far distance, KT had to employ the strategy of partial scanning.