Then he groped for the candle. By experiment he found that at a distance of a foot or so the illumination registered. Then there was no paralysis of the nerve itself. Desperately he marshalled his unruly thoughts, striving to look back into the remote past of his student days. Fragments of knowledge came to him, but nothing on which to build a theory of what was wrong.
"It's mechanical; it's mechanical," he muttered over and over to himself, but could not seem to progress beyond this point. All he could conclude was that it was not ophthalmia or trachoma. He had seen a good deal of these two plagues of Egypt, and their symptoms were absent here. He concentrated until his mind was weary, and his will slipped. At last in despair he relaxed and in an unconscious gesture rubbed his eyes with his forefingers and thumbs. The contact brought him to with a jerk.
The eyeballs, instead of feeling soft and velvety under the lids, were as hard as marbles.
The shock of this phenomenon rang a bell in his memory. A distinct picture came to him of his classroom and old Doctor Stokes. He could fairly hear the slow, impressive voice.
"There is one symptom," the past was saying to him, "one symptom, young gentlemen, that is not always present; but when present establishes the diagnosis beyond any doubt. I refer to a peculiar hardening of the eyeball itself----"
"Glaucoma!" cried Kingozi aloud.
His thoughts, like hounds on a trail, raced off after this new scent. Desperately he tried to recollect. In snatches he captured knowledge. Of its accuracy he was sometimes in doubt; but little by little that doubt grew less. To change the figure, the latent images of his past science developed slowly, like the images on a photographic plate.
Glaucoma--a hardening, an enlarging of the pupil, a change in the shape and consistency of the iris--yes, he had it fairly well. Treatment? Let's see--an operation on the iris, delicate. That was it. Impossible, of course. But there was something else, a temporary expedient, until the surgeon could be reached--an undue expansion of the pupil----
"Why," shouted Kingozi aloud, sitting up in bed. "Pilocarpin, of course!"
What luck! He fervently blessed the shortage of phenacetin that had forced him to take pilocarpin as a sweating substitute for fever.