Light and Perception

• As a person looks out at the world, light enters his eyes and stimulates a group of sensitive cells at the back of the eyeballs. These cells form the retina in an eye. The retina converts light into electrical signals that are sent to the brain through the optic nerve. This system of visual processing is connected to the nervous system, thus affecting moods and feelings of well-being as an individual scans the environment around him.
  
  

Natural and Artificial Light

• The natural light of the sun is created by blending a spectrum of colors, ranging from red to violet. Each of these colors are of a different wavelength and visible by shining light through a prism. There also are wavelengths of light that are not visible to the naked eye but still affect us, including infrared and ultraviolet. The healthy development of plants and animals depends on the mixture of all the colors in specific proportions to create sunlight. Hormone production in humans is initiated in response to the skin's exposure to this light.
  
  Artificial light from bulbs and fixtures produces an illumination with imbalances in color reproductions. For example, incandescent light bulbs produce a yellowish-orange light, while fluorescent bulbs tend to create a blend of yellow and green light.
  
  

Effects on Emotions

• Different colors of light can affect mood. Blue light creates a soothing affect, while red encourages a feeling of excitement and passion. Modern nightclubs are settings in which the visual environment created by different colors of light is specifically designed to elicit a pleasurable emotional response.
  
  Imbalances in lighting also can affect our moods through their negative physical effects. A room that is overly bright can produce eye strain, accompanied by a sense of tension. Alternately, poor illumination can contribute to sadness and depression. Such negative effects result after a lack of planning and foresight in the use of lighting in living spaces. This can be a particular problem in the workplace where productivity is affected by the emotional and psychological effects of artificial illumination.
  
  

Light Design

• Lighting design can be used to enhance a person's emotional health in the home. In areas of the house where there is a lot of physical activity or movement, such as the kitchen, bright lighting contributes to an active and vibrant atmosphere. In rooms associated with relaxation, low-level lighting design allows occupants to rest after the day's challenges. The best source of light in the home for positive emotions is still sunlight; ensuring curtains are open in the daytime contributes to a sense of confidence and well-being.