Page:Proceedings of the Royal Society of London Vol 4.djvu/330

Rh his visual perception as being that of an extensive field of light, in which everything appeared dull, confused, and in motion, and in which no object was distinguishable. On repeating the experiment two days afterwards, he described what he saw as a number of opake watery spheres, which moved with the movements of the eye, but when the eye was at rest remained stationary, and their margins partially covering one another. Two days after this the same phe- nomena were observed, but the spheres were less opake and some- what transparent ; their movements were more steady, and they ap- peared to cover each other more than before. He was now for the first time capable, as he said, of looking through these spheres, and of perceiving a difference, but merely a difference, in the surround- ing objects. The appearance of spheres diminished daily; they be- came smaller, clearer, and more pellucid, allowed objects to be seen more distinctly, and disappeared entirely after two weeks. As soon as the sensibility of the retina had so far diminished as to allow the patient to view objects deliberately without pain, ribands differently coloured were presented to his e^^e. These different colours he could recognize, with the exception of yellow and green, which he fre- quently confounded when apart, but could distinguish when both were before him at the same time. Of all colours, gray produced the most grateful sensation : red, orange and yellow, though they excited pain, were not in themselves disagreeable ; while the effect of violet and of brown was exactly the reverse, being very disagreeable, though not painful. Brown he called an ugly colour: black pro- duced subjective colours ; and white gave rise to a profusion of musccz volitantes. When geometrical figures of different kinds were offered to his view, he succeeded in pointing them out coiTectly, although he never moved his hand directly and decidedly, but always as if feeling mth the gi'eatest caution. When a cube and a sphere were presented to him, after examining these bodies Tvith great attention, he said that he saw a quadrangular and a cu'cular figure, and after further consideration described the one as being a square, and the other a disc, but confessed that he had not been able to form these ideas until he perceived a sensation of what he saw in the points of his fingers, as if he really touched the objects. Subsequent experi- ments showed that he could not discriminate a sohd body from a plane surface of similar shape ; thus a pyramid placed before him, with one of its sides towards his eye, appeared as a plane triangle.

Two months after the above-mentioned operation, another was performed on both eyes, for the cure of the congenital strabismus, by the division of the tendons of the recti interni muscles, which pro- duced a very beneficial effect on the vision of the left eye ; and even the right eye, which had been amam'otic, gained some power of per- ceiving light, and, from being atrophied, became more prominent. Stni it was only by slow degrees that the power of recognizing the true forms, magnitudes, and situations of external objects was ac- quired. In course of time, the eye gained gi'eater power of con- verging the rays of light, as was shown by the continually iacreasing capacity of distinct vision by the aid of spectacles of given powers.