Fritz Heider, The life of a psychologist. Lawrence: University Press of Kansas, 1983, pp. 5 and 30—
My brother and I had little cap pistols [at around the age of ten]. These caps seemed to have remarkable properties, and I decided to experiment to find out more about them. The upshot was that something exploded in my face. Several small pieces of lead became embedded in my cheeks and forehead, and a few entered my left eye, injuring the retina. My father took me to our doctor right away. He was rather pessimistic about the outlook for the eye. I remember that I had to stay in bed for two weeks, with my eyes covered. I had no pain as I lay there, but I had a dim feeling that something of importance had happened which would influence my whole life. I could not judge whether this would be beneficial or harmful—I only knew that there was something serious about it, though I do not remember that I was unduly worried.…
[Ten years later, during World War I] I tried several times to enter the military service. I began to wonder whether I was rejected because the draft board considered the possibility that my injured eye might become infected and affect the healthy eye. So, on one bleak, wintry day in 1916 I went to the hospital, accompanied by my father, and had the damaged eye removed, to be replaced by an artificial one. But even after that change in my physical condition, I was not taken on.