"This cleft was situated so far from the center of the pupil that it was entirely covered by the iris. With this eye the patient had a perception of light, and was even capable of perceiving colors of an intense and decided tone. He believed himself, moreover, able to perceive about one third of a square inch of any bright object, if held at the distance of half an inch or an inch from the eye, and obliquely in such a direction as to reflect the light strongly toward the pupil. But this, I am convinced, was a mere delusion, for all rays of light falling in the direction of the optic axis must have been intercepted and reflected by the opaque capsule. By these rays, therefore, a perception of light, indeed, might be conveyed, but certainly no perception of objects. On the other hand, it seems probable that the lateral cleft in the capsule permitted rays of light to pass into the interior of the eye. But as this small aperture was situated entirely behind the iris, those rays only would have permeated which came in a very oblique direction from the temporal side. Admitting, then, these rays of light to pass through the cleft, still on account of their obliquity they could produce but a very imperfect image, because they impinged upon an unfavorable portion of the retina. Moreover, I satisfied myself by experiments, that the patient could not in the least discern objects by sight. My experiments led me to the conclusion that his belief that he really saw objects resulted solely from his imagination combined with his power of reasoning. In feeling an object and bringing it in contact with the eyelids and the cheek, an idea of the object was produced, which was judged of and corrected according to the experience he had gained by constant practice.
"The patient's sense of touch had attained an extraordinary degree of perfection. In order to examine an object minutely he conveyed it to his lips.
"On the 10th of July, 1840, I performed an operation on the left eye. The light was so painful to him that I could not try any experiments immediately after the operation. Both eyes were closed with narrow strips of court-plaster, and treated with iced water for forty-eight hours. The patient suffered from muscæ volitantes, and could not bear even a mild degree of light falling on the closed lids. After the lapse of a few weeks, the muscæ volitantes were greatly mitigated, and the intolerance of light ceased.
"On opening the eye for the first time on the third day after the operation, I asked the patient what he could see; he answered that he saw an extensive field of light, in which everything appeared dull, confused, and in motion. He could not distinguish objects. The pain produced by the light forced him to close the eye immediately.
"Two days afterward the eye, which had been kept closed by means of court-plaster, was again opened. He now described what he saw as a number of opaque watery spheres, which moved with the movements of the eye, but when the eye was at rest remained stationary, and then partly covered each other. Two days after this the eye was again opened. The same phenomena were again observed, but the spheres were less opaque and somewhat transparent; their movements more steady; they appeared to cover each other more than before. He was now for the first time able, as he said, to look through the spheres, and to perceive a difference, but merely a difference, in the surrounding objects. When he directed his eye steadily toward an object, the visual impression produced by the object was painful and very imperfect, because the eye, on account of its intolerance of light, could not be kept open long enough for the formation of the idea as derived from visual sensation. The appearance of spheres diminished daily; they became smaller, clearer, and more pellucid, allowed objects to be seen more distinctly, and disappeared entirely after two weeks. The muscæ volitantes, which had the form of black, immovable, and horizontal stripes, appeared, every time the eye was opened, in a direction upward and inward. When the eye was closed he observed, especially in the evening, in an outward and upward direction, an appearance of dark blue, violet, and red colors; these colors became gradually less intense, were shaded into bright orange, yellow, and green, which latter colors alone eventually remained, and in the course of five weeks disappeared entirely. As soon as the intolerance of light had so far abated that the patient could observe an object without pain, and for a sufficient time to gain an idea of it, the following experiments were made on different days.
"First Experiment.—Silk ribbons of different colors, fastened on a black ground, were employed to show the complementary colors. The patient recognized the different colors, with the exception of yellow and green, which he frequently confounded, but could distinguish when both were exhibited at the same time. He could point out each color correctly when a variety was shown him at the same time. Gray pleased him best; the effect of red, orange, and yellow was painful; that of violet and brown not painful, but disagreeable. Black produced subjective colors, and white occasioned the recurrence of muscæ volitantes in a most vehement degree.
"Second Experiment.—The patient sat with his back to the light, and kept his eye closed. A sheet of paper on which two strong black lines had been drawn, the one horizontal, the other vertical, was placed before him, at the distance of about three feet. He was now allowed to open the eye, and after attentive examination he called the lines by their right denominations. When I asked him to point out with his finger the horizontal line, he moved his hand slowly, as if feeling, and pointed to the vertical; but after a short time, observing his error, he corrected himself. The outline in black of a square [six inches in diameter], within which a circle had been drawn, and within the latter a triangle, was, after careful examination, recognized and correctly described by him. When he was asked to point out either of the figures, he never moved his hand directly and decidedly, but always as if feeling, and with the greatest caution; he pointed them out, however, correctly. A zigzag and a spiral line, both drawn on a sheet of paper, he observed to be different, but could not describe them otherwise than by imitating their forms with his finger in the air. He said he had no idea of those figures.
"Third Experiment.—The windows of the room were darkened, with the exception of one, toward which the patient, closing his eye, turned his back. At the distance of three feet, and on a level with the eye, a solid cube and a sphere, each of four inches diameter, were placed before him. I now let him open his eye. After attentively examining these bodies, he said he saw a quadrangular and a circular figure, and after some consideration he pronounced the one a square and the other a disk. His eye being then closed, the cube was taken away, and a disk of equal size substituted and placed next to the sphere. On again opening his eye he observed no difference in these objects, but regarded them both as disks. The solid cube was now placed in a somewhat oblique position before the eye, and close beside it a figure cut out of pasteboard, representing a plane outline prospect of the cube when in this position. Both objects he took to be something like flat quadrates. A pyramid, placed before him with one of its sides toward his eye, he saw as a plane triangle. This object was now turned a little, so as to present two of its sides to view, but rather more of one side than of the other; after considering and examining it for a long time, he said that this was a very extraordinary figure; it was neither a triangle, nor a quadrangle, nor a circle; he had no idea of it, and could not describe it. 'In fact,' said he, 'I must give it up.' On the conclusion of these experiments I asked him to describe the sensations the objects had produced, whereupon he said that immediately on opening his eye he had discovered a difference in the two objects, the cube and the sphere, placed before him, and perceived that they were not drawings; but that he had not been able to form from them the idea of a square and a disk, until he perceived a sensation of what he saw in the points of his fingers, as if he really touched the objects. When I gave the three bodies, the sphere, cube, and pyramid, into his hand, he was much surprised that he had not recognized them as such by sight, as he was well acquainted with them by touch. These experiments prove the correctness of the hypothesis I have advanced elsewhere on the well-known question put by Mr. Molyneux to Locke, which was answered by both these gentlemen in the negative.
"Fourth Experiment.—In a vessel containing water to about the depth of one foot was placed a musket-ball, and on the surface of the water a piece of pasteboard of the same form, size, and color as the ball. The patient could perceive no difference in the position of these bodies; he believed both to be upon the surface of the water. Pointing to the ball, I desired him to take up this object. He made an attempt to take it from the plane of the water; but, when he found he could not grasp it there, he said he had deceived himself, the objects were lying in the water, upon which I informed him of their real position. I now desired him to touch the ball which lay in the water with a small rod. He attempted this several times, but always missed his aim. He could never touch the object at the first movement of his hand toward it, but only by feeling about with the rod. On being questioned with respect to reflected light, he said that he was always obliged to bear in mind that the looking-glass was fastened to the wall in order to correct his idea of the apparent situation of objects behind the glass.
"When the patient first acquired the faculty of sight, all objects appeared to him so near that he was sometimes afraid of coming in contact with them, though they were in reality at a great distance from him. He saw everything much larger than he had supposed from the idea obtained by his sense of touch. Moving and especially living objects, such as men, horses, etc., appeared to him very large. If he wished to form an estimate of the distance of objects from his own person or of two objects from each other without moving from his place, he examined the objects from different points of view by turning his head to the right and to the left. Of perspective in pictures he had, of course, no idea; it appeared to him unnatural that the figure of a man represented in the front of a picture should be larger than a house or mountain in the background. All objects appeared to him perfectly flat. Thus, although he very well knew by his touch that the nose was prominent and the eyes sunk deeper in the head, he saw the human face only as a plane. Though he possessed an excellent memory, this faculty was at first quite deficient as regarded visible objects: he was not able, for example, to recognize visitors, unless he heard them speak, till he had seen them very frequently. Even when he had seen an object repeatedly he could form no idea of its visible qualities without having the real object before him. Heretofore when he dreamed of any persons, of his parents, for instance, he felt them and heard their voices, but never saw them; but now, after having seen them frequently, he saw them also in his dreams. The human face pleased him more than any other object. Although the newly-acquired sense afforded him many pleasures, the great number of strange and extraordinary sights was often disagreeable and wearisome to him. He said that he saw too much novelty which he could not comprehend; and, even though he could see both near and remote objects very well, he would nevertheless continually have recourse to the use of the sense of touch."