Reports

Blind man living in normal society has circadian rhythms of 24.9 hours

Science  28 Oct 1977:
Vol. 198, Issue 4315, pp. 421-423
DOI: 10.1126/science.910139

Abstract

A psychologically normal blind man, living and working in normal society, suffered from a severe cyclic sleep-wake disorder. Investigations showed that he had circadian rhythms of body temperature, alertness, performance, cortisol secretion, and urinary electrolyte excretion which were desynchronized from the 24-hour societal schedule. These rhythms all had periods which were longer than 24 hours and indistinguishable from the period of the lunar day.