The living organism cannot exist without light. Only in the presence of light do the plants accomplish photosynthesis and the human body synthesize the Vitamin D, essential component for the calcium retention in the bones.
The light not only that sustains life but it can also heal.
The recent studies have shown that the depression, especially the one related to the cold season, can be treated by daily exposure to the white light.
The light therapy is administrated usually through a certain device called light box, a metallic structure containing a tube of fluorescent light put behind a screen.
The dosage of light exposure is calculated by measuring the intensity and the length of the exposure. Most of the studies monitoring to the light therapy, recommend an exposure of two to six hours a day. At a certain level the intensity of light is reversed as proportion to the time of exposure.
The light therapy used for treating depression is best applied very early in the morning after the patient has woken up. Under no circumstances should it be performed before going to bed because it is known to cause insomnia.
The younger persons are the ones responding the best to the light. Also the light therapy has a higher efficiency rate in the somnolence and large appetite treatment or in the case a person gains weight with no reason.