Caracerization of activity-rest cycle, light exposition and sleep quality in blind subjects.
biological ritmicity, blindness, synchronization, non-photic markers.
It is estimated that 50% of blind people who do not perceive light consciously are unable to synchronize with the 24-hour day. Since non-photic time lanes would not be sufficient to synchronize individuals with vision loss. Considering that the studies that characterized this population were carried out in the northern hemisphere in places with high latitude and consequent wide seasonal variation, the objective of this study was to characterize the pace of activity and rest, the rhythm of exposure to light and sleep quality of the blind in the city of Natal - RN - Brazil, which is located at a low latitude, near the equator, with little seasonal variation. For this, we used actimetry to characterize circadian rhythm, and questionnaires to characterize the chronotype, daytime sleepiness, sleep quality, insomnia, risk of obstructive sleep apnea, as well as questions related to the perception of light and time. The sample consisted of 22 blind people who answered the questionnaires and among them 14 used the actimeter for approximately 20 days. Therefore, we observed that unlike that classically found in the literature, no participant was in free course, both by actimetry and by the results of the questionnaires, which indicate that they do not have severe sleep-related problems. Thus, we verified four factors that can explain the adjustment of this sample with the 24-hour day, which are: environmental (temperature and luminosity), social (regular working and study times and daily interaction with other people), physical activity and use of electronic devices (especially mobile devices). We verified that the main differential of this work with the other ones already performed with non-photic synchronizers is that currently the entire population has easy access to the cell phone. That in the case of the blind is a tool used at all times, which facilitates their routine, especially mobility and communication. However, this cell phone is also helping the adjustment of these blind people, since it is a means of constant temporal information.