Previous to two decades before this writing, hundred-weights of literature had been published on the causation of the numerous organic diseases of the eye by diseases elsewhere in the body ; and since the popularization of the doctrine of focal infection, this literature has been added to by tons.
But the other side of the picture, how much functional disturbance elsewhere in the body can originate from the eyes, has not been given the recognition that its importance deserves.
Some phases of this subject have been set forth in my previous papers.1
Aside from giving due recognition to the late Dr. George M. Gould for the great pioneer work done in this field, no effort will be made to give all references to authorities quoted, or to compile statistics, and figures and formulas will be cut down to the fewest possible.
As knowledge advances, the tendency to consider visible gross