One of the most physiologically demanding things that older people do every day is to get up
in the morning. After spending a night laying flat, where the blood distributes evenly across
the body, when they stand in the morning (and the blood rushes to their feet), their
cardiovascular system may not be able to compensate and maintain blood flow to the brain.
This phenomenon is known as orthostatic or postural hypotension. The investigators have found
in a group of young individuals that use of a dawn-simulation light that gradually wakes the
brain is able to increase cardiovascular tone prior to arising. The goal of this experiment
is to determine whether this dawn simulation light is able to increase cardiovascular tone in
older adults such that they would have reduced or absent postural hypotension when they
awaken in the morning. This would greatly reduce the risks of falls and their associated
morbidities in older adults.