THE SUBJECTS for this research were all former Far-Eastern prisoners of war. As their visual histories dated from 1939 to the time of writing, a period of over 10 years is thereby covered. Whatever the cause of this strange ailment may be—and there may be more than one explanation of it—prior to World War II very few cases were on record to help in understanding it. A different state of affairs exists now. A wealth of literature has accumulated, some written by men on the spot, in the prison camps; some by those who, like myself, studied the subjects soon after their release. While it may be argued that one now knows all that is to be known about the clinical manifestations of this disease, the fact remains that few authors agree in every particular. An attempt to clarify the clinical picture should in itself, then, be worth while. The