Don't you find that it is getting increasingly darker every day when you wake up for school ? As winter comes ,days become shorter while the nights become longer ,In the past people slept more in winter ,but in modern times we just use more electric light instead of sunlight to continue our normal routines . But scientific research is finding that manhandling of electric light is making us sick . Electric light is fooling the body's biological clock into releasing awaking hormones ( )at the wrong times ,scientists say .This might be leading to seasonal fatigue  and depression . Much more than mental health is at stake ,Recent scientific studies have found that women who work at night ,have higher chances of getting breast-cancer . "Electric lights are wonderful ,but as with a lot of other things ,we really mess ,things up "said David Avery ,a psychiatrist  ." Our ancestors evolved in a very regular light -dark cycle ,and our bodies just work better that way ." Researchers have known for a long time that all living things have a biological clock that is linked to light ,Being of the natural day-night cycle can cause fatigue ,mood change and depression ,This is known as seasonal affective disorder ,or SAD. Scientists disagree on the cause of SAD ,Some say it is caused by winter's late sunrises , others blame the early sunsets . However ,they all agree the perfect solution to SAD is to give up artificial light ,It will quickly bring someone into a cycle of long ,restful nights and easy awakenings at dawn . But realistically most people need to use electric light in their everyday life . Ironically the next best solution is to use more bright lights to reset the body's biological clock . By getting bright light first thing in the morning it simulates  an earlier dawn and shifts the body clock forward ,according to Alfred Lewy ,a psychiatrist at Oregon Health & Science University . A 2005 study done by the American Psychiatric Association showed that daily exposure to bright light was about as effective as medicine used to treat several forms of depression . According to the text ,electric light is bad for health mainly because   _
is shortens people's sleeping time it makes people upset and unable to concentrate it releases radiation and increases people's chances of getting sick it stimulates the body to release awaking hormones at the wrong time