Late effects of early visual deprivation on state control in sleep were studied in 23 infants with bilateral congenital cataract before and after surgery (usually, on the 6th month of life). In the course of three years 67 observations were performed. Laboratory assessments included videotaping infant sleep behaviour, recording EEG, EOG, ECG, galvanic skin response. It was shown that the early visual deprivation led to general changes in the basic mechanisms underlying state control in infancy. The sleep stages (active and quiet sleep), their duration and physiological autonomic and central characteristics were modified as compared to the age norm over a protracted period after surgery, when the visual experience became available for the infant. This type of sleep cycle can be identified as "partially perinatal sleep pattern". Revealed peculiarities of sleep cycle organization were suggested to reflect the higher level of activation in the neural arousal systems owing to the deficit of environmental stimulation during the critical stage (2-4 months) of brain development.