The history of Nietzsche's eye trouble makes it probable that not simply a defect in his eyes themselves, but a deeper condition behind them was responsible. Up to the age of 15 he was a model scholar. Essential eye defects of refraction should make themselves felt during childhood. Then, with adolescence, he changed. Adolescence is one of the red-letter epochs for the pituitary, when its growth and enlargement precedes and stimulates the ripening of the sex cells in the reproductive organs. Until adolescence ended and physical development ceased, his intellectual interests were nil, and he was particularly backward in mathematics. Colds and coughs, and recurring pains in the head and eyes bothered him (colds and coughs are frequent in those whose pituitary expansion is limited by the bony sella turcica to any extent). After his puberty, migraine definitely became his demon companion. Following the diphtheria in the army (which must have damaged his adrenals), the attacks grew much worse, and complaints about them more bitter because the pituitary now, in addition to its own burden, had to compensate for the insufficient adrenals. So "his frequent illness made him more and more a subject of treatment and commiseration.... If only my eyes would hold out ... it seems to me at the age of 30 as if I had lived 60 years ... very frequent sufferings of stomach, head and eyes ... acidity oppresses me, and everything except the tenderest food becomes acid.... I cannot doubt that I am the victim of a serious cerebral disease, and that stomach and eyes suffer only from this central cause ... half-dead with pain and exhaustion." In December 1888, he fell, had to be helped home, lay silent for two days, then became loud, active and unbalanced. The attack was preceded by the drinking of much water.