Page:Proceedings of the Royal Society of London Vol 1.djvu/275

Rh everything presented to him touched his eye, and still continued to call every object red.

After couching, the inﬂammation which followed was not so con- siderable as in the former case; but this cataract was also ﬂuid, and, from its diffusion through the aqueous humour, occasioned a tempo- rary opacity, which concealed for a time an opacity of the capsule, which rendered the sight permanently imperfect.

It was not till the end of four weeks from the second operation that the sight was again examined, when it was found that he had ac- quired some knowledge of colours and of the distances of objects, which no longer appeared to touch his eye; but he could not be said to have acquired any diseernment of ﬁgure.

The second opportunity which Mr. Home had of making similar experiments was in a boy of seven years of age, who had been blind from his birth by cataracts in both eyes. His blindness, however, was not so complete as in the preceding case : his pupil contracted considerably when a lighted candle was placed before it, and by day- light he could distinguish many colours with tolerable accuracy, par- ticularly the more vivid ones. The operation of couching was again preferred in this case, with the hope of avoiding inﬂammation. It gave very little pain, and was attended with the desired success.

As it was hoped that the eye would be but little disturbed by the operation, Mr. Home was prepared to examine his perception of ob- jects as soon as the operation was over. After the eye had been allowed ten minutes to recover itself, a round piece of card of a yel- low colour was placed about six inches from it. He immediately said that it was yellow; but upon being asked the shape, he ex- pressed 3 wish to touch it. Upon this being refused, he continued to look at it, and at length guessed that it was round; and when a square blue card was put before him, he said that this was blue, and round also. A triangular piece he also called round. With regard to the distance of objects, he could form no judgement, but did not even at ﬁrst suppose that any of them touched his eye.

The pleasure which this boy received from receiving his sight was such, that it was found impossible to restrain him from using it. The experiments were consequently repeated, and carried further at the distance of about two hours from the operation. Upon being desired to examine a square card with attention, he after some time said, he had found a corner, and then readily counted four corners; and in the same manner counted three angles of a triangle, by run. ning his eye along the edges from corner to corner. He was on various occasions deceived, as might be expected, by the different apparent magnitudes of the same body at different distances: a guinea at ﬁfteen inche‘s distance was taken for a seven shilling piece ; but at ﬁve inches he thought it a guinea. Upon seeing a cart from a two pair of stairs window, he took it for a wheelbarrow drawn by a dog, and counted the number of horses in other carts, supposing them to be dogs. At the end of a fortnight, when the different pieces of card were placed before him, he could not immediately tell