Reading this book about biological clocks,
and picked up these fun facts:
1) there are light receptors in the
eye that apparently are never used for vision: their function is to
inform the clock center (there is one) about the amount of light.
Blind people may or may not still have the use of these receptors: if
they don't their biological clock won't synchronize with day and
night properly. If they do, they synchronize as well as sighted
people.
2) It's a LOT brighter outdoors than indoors. Even on a dark
day, lots more light showering down outside than in a brightly-lit
room. The numbers really surprised me. If you're having trouble
synchronizing your clock with the day and night cycle, getting
outside as soon as you wake up will probably do you a lot more good
than dimming the lights before bedtime.
3) People vary, but most
commonly, if kept in a space with nothing to reveal what time of day
it is, most people will settle to a circadian cycle longer than 24 hours. So the system
*tends* to run late. If you don't keep nudging the clock by getting
that blast of light in the morning, the natural tendency will be to
stay up a bit later every night.
Point three explains something of my husband's sleep patterns - to bed late, even later to rise and often tired despite much sleep.....
ReplyDeleteThank you for this very useful post.
ReplyDelete