World Sleep Day shines light on slumber

Editor's Note: March 21st is the annual World Sleep Day, which draws society's attention to the burdens of sleep problems. Human beings and animals alike need to sleep to obtain energy. Let's take a look at some especially relevant pictures for this day.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Next   >>|