[Disorders of wakefulness and sleep in blind patients]

The goal of this paper was to summarize three studies focused on sleep/wake disorders in blind subjects. The first study was an epidemiology survey performed in 1073 blind subjects in comparison with non-blind controls. The blind had more episodes of insomnia and free running rhythms. They also took more sleeping pills and complained of more daytime somnolence. The seriousness of the sleep disorders was related to the seriousness of the blindness. In the second study, 78 blind children were compared with seeing children. They had more insomnia and more parasomnias but there was not any more free running. Finally, polysomnography was performed in 26 free running blind subjects in comparison with 26 controls. Total sleep time and sleep efficiency were lower in the blind. Sleep latency was increased and REM sleep was disturbed (longer latency and percentage decreases). There was no difference concerning slow wave sleep. Factorial analysis showed that factors such as being born blind, having ocular prosthesis, being single or having children had no influence on sleep. Working did however have an influence.