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.
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