Scientists from Boulder conducted an experiment which shows that it is worth turning off the light before bedtime. It turns out that it is not advisable for preschoolers to stay in bright light before going to bed. Excess light in the evening time inhibits the production of the hormone – melatonin and makes it difficult for children to fall asleep. In addition, it can also cause sleep problems in the following days, says Physiological Reports.
A group of 10 children aged 3-5 was subjected to the study. It lasted for seven days. During the first five days, each child was subjected to rigorous burial control. The idea was for their biological clock to get in sync and their melatonin levels to rise at about the same time.
On the sixth day of the experiment, scientists at the University of Colorado in Boulder collected saliva samples from each child under controlled dim lighting conditions. Thanks to this, they could control the process of melatonin secretion.
On the final day, the children spent time in a darkened room, then invited them to play at a 1000 lux table for an hour, and then collected saliva samples.
Sample analysis showed that exposure to bright light for an hour practically inhibited the production of sleep-essential melatonin in the child’s body and remained at a reduced level for 50 minutes after the lights were turned off. Studies carried out on adults have shown that the effects were much smaller.
Children may be more sensitive to light than adults, possibly due to a different eye structure, incl. they have larger pupils and a more transparent lens.