In the dark winter months, our bodies crave light and if we don't receive it, our poor shrivelled selves can develop Seasonal Affective Disorder.  This is a medically recognised disorder whereby lack of light results in symptoms such as depression, lethargy and lack of energy.  Light therapy is increasingly being used to reset our body clocks -- no matter how or why they've been put off track. Research shows that light therapy may have potential for treatment of several other disorders in addition to SAD (Seasonal Affective Disorder).