Final Remarks.
To the seven reports upon cases of persons born blind and afterward surgically treated, which are here presented in abridged form from the English originals, may be added some more recent and more accessible ones, one by Hirschberg ("Archiv für Opthalmologie," xxi, 1. Abth., S. 29 bis 42, 1875), one by A. von Hippel (ibid., xxi, 2. Abth., S. 101), and one by Dufour ("Archives des Sciences physiques et naturelles," lviii, No. 242, April, 1877, p. 420). The cases reported here are those most discussed. I have given them considerably in detail in order that the reader may form an independent judgment concerning the behavior of persons born blind and then operated upon, as that behavior is described before the modern physiological controversy over empiricism and nativism. Helmholtz ("Physiologische Optik," § 28) mentions, besides those of Chesselden and Wardrop and Ware, which he gives in abridged form, some other cases also. Others still may be found in Froriep's "Notizen" (xi, p. 177, 1825, and iv, p. 243, 1837, also xxi, p. 41, 1842), partly reported, partly cited (the latter according to Franz).
In addition to the cases here given of persons born blind and then surgically treated—persons not able to see things in space-relations before becoming blind—one more case is to be mentioned; it is that of a girl who in her seventh year (probably in consequence of the effect of dazzling sunlight) lost her sight completely, but recovered it again at the age of seventeen years after being treated with electricity. She had to begin absolutely anew to learn to name colors like a child; all measure of distance, perspective, size, had been lost for her by lack of practice (as O. Heyfelder relates in his work "Die Kindheit des Menschen," second edition, Erlangen, 1858, pp. 12-15). He says, p. 12, that the patient had been eight years blind; p. 13, that she had been ten years so. Such cases prove the great influence of experience upon vision in space, and show how little of this vision is inborn in mankind.
When we compare the acquirement of sight by the normal newly-born child and the infant with that of those born blind, we should, above all, bear in mind that the latter in general could make use of only one eye, and also that on account of the long inactivity of the retina and the absence of the crystalline lens, as well as in consequence of the numerous experiences of touch, essential differences exist. Notwithstanding this, there appears an agreement in the manner in which in both cases vision is learned, the eye is practiced, and the association of sight and touch is acquired. The seventh case in particular shows plainly how strong the analogies are.
These cases are sufficient to refute some singular assertions, e. g., that all the newly-born must see objects reversed, as even a Buffon ("Œuvres complètes," iv, 136; Paris, 1844) thought to be the fact. My boy, when I had him write, in his fifth year, the ordinary figures after a copy that I set for him, imitated the most of them, to my surprise, always in a reversed hand (Spiegelschrift, "mirror-hand"); the 1 and the 4 he continued longest to write thus, though he often made the 4 the other way, too, whereas he always wrote the 5 correctly. This, however, was, of course, not owing to imperfect sight, but to incomplete transformation of the visual idea into the motor idea required for writing. Other boys, as I am given to understand, do the same thing. For myself, I found the distinction between "right" and "left" so difficult in my childhood, that I remember vividly the trouble I had with it.
Singularly enough, Buffon assumed, in 1749, that the neglect of the double images does not yet take place at the beginning of life. Johannes Müller, in 1826, expresses the same view. But, inasmuch as in the first two or three weeks after the birth of a human being, in contrast with many animals, nothing at all can as yet be distinctly seen, it is not allowable to maintain that everything must be seen double. Rather is it true that everything is seen neither single nor double, since the very young child perceives, as yet, no forms (boundary-lines) and no distances, but merely receives impressions of light, precisely as is the case with the person born blind, in the period directly after an operation has been performed upon his eyes.
Schopenhauer (in his treatise on "Sight and Colors," first edition, Leipsic, 1816, p. 14) divined this truth. He says, "If a person who was looking out upon a wide and beautiful prospect could be in an instant wholly deprived of his intellect, then nothing of all the view would remain for him except the sensation of a very manifold reaction of his retina, which is, as it were, the raw material out of which his intellect created that view."
The new-born child has, as yet, no intellect, and therefore can not, as yet, at the beginning, see; he can merely have the sensation of light.
This opinion of mine, derived from observation of the behavior of newly-born and of very young infants (cf. the first chapter of this book), seems to me to be practically confirmed in an account given by Anselm von Feuerbach in his work on Kaspar Hauser (Anspach, 1832, p. 77).
"In the year 1828, soon after his arrival in Nuremberg, Kaspar Hauser was to look out at the window in the Vestner Tower, from which there was a view of a broad and many-colored summer landscape. Kaspar Hauser turned away; the sight was repugnant to him. At a later period, long after he had learned to speak, he gave, when questioned, the following explanation: