Those of us who regularly burn the midnight oil ... may be at risk of depression and learning issues... and while a lack of sleep doesn't help, Johns Hopkins Researchers say the culprit is light.
They found that when mice were routinely exposed to bright light at night -- special cells in their eyes were activated -- affecting the part of the brain linked to mood, memory and learning.
The mice had elevated levels of the stress hormone -- which triggered depression and decreased cognitive functioning.
Researchers recommend using fewer lamps during the evening hours and stick to less intense light bulbs.