Reading in Dim Light

• Straining eyes in dim light can cause headaches.BananaStock/BananaStock/Getty Images
  
  According to a 2007 UK Guardian article, reading with low or no light does not permanently weaken eyesight. However, the lack of light does cause stress on the eye, and temporary side effects include difficulty reading and headaches. "Suboptimal lighting can create a sensation of having difficulty in focusing," the article noted. "It also decreases the rate of blinking and leads to discomfort from drying. The important counterpoint is that these effects do not persist." Office employees who need to do a lot of reading should remember to keep a light on if possible to avoid strain.
  
  

Seasonal Affective Disorder

• An SAD florescent light can decrease symptoms like lethargy and social withdrawal.Todd Warnock/Lifesize/Getty Images
  
  Seasonal Affective Disorder (SAD) is a mental condition where the decreased amount of sunlight associated with fall and winter months can cause depression or negative mood. SAD has an impact on work performance and energy in the office place and on an individual's personal life. The treatment for SAD is light therapy during fall and winter with a special florescent light that mimics the light generated by the sun.
  
  

Lack of Sunlight from Working Underground

• The dim light of underground mines can have a negative effect on mental health.Jupiterimages/Photos.com/Getty Images
  
  Working underground in a lack of sunlight can have negative effects on mental health; this became a hot button issue in 2010 following the more than 60-day captivity of the Chilean miners. According to comments from Dr. Ryan A. Stanton, medical director of Good Samaritan Hospital in Lexington, Kentucky, miners who go too long without sunlight can develop a depression similar to SAD. The Occupational Safety and Health Administration puts requirements on how long miners are allowed to be underground, in part for respiratory concerns, but also in part to ensure miners receive adequate amounts of sunlight.
  
  

Vitamin D Deficiency

• Milk is an excellent source of Vitamin D for those who work with a lack of natural light.Jupiterimages/Comstock/Getty Images
  
  Vitamin D is an essential tool the body uses to process phosphorus and calcium. One of the main ways to intake Vitamin D is by absorbing sunlight. Working indoors or in the dark with a lack of natural light can lead to Vitamin D deficiency, also known as rickets. Rickets can cause the bones to weaken or soften, stunt growth and in rare cases cause skeletal deformations. The U.S. Library of Health recommends that those working in dark places eat plenty of fish, liver and processed milk to keep up Vitamin D intake.