Background Paragraph: Medical research on the effects of excessive light on the human body suggests that a variety of adverse health effects may be caused by light pollution or excessive light exposure, and some lighting design textbooks[33] use human health as an explicit criterion for proper interior lighting. Health effects of over-illumination or improper spectral composition of light may include: increased headache incidence, worker fatigue, medically defined stress, decrease in sexual function and increase in anxiety.[34][35][36][37] Likewise, animal models have been studied demonstrating unavoidable light to produce adverse effect on mood and anxiety.[38] For those who need to be awake at night, light at night also has an acute effect on alertness and mood.[39]. 
Story: Two friends, John and Abe, worked at the same warehouse. John was exposed to very strong light all the time, while Abe worked in a  more normal environment. John started experiencing health problems after a while.
Which friend worked in a healthier work environment, John or Abe? Which friend worked in a less healthy work environment, John or Abe? Which worker experienced fewer adverse effects on mood and anxiety, John or Abe? Which worker experienced more adverse effects on mood and anxiety, John or Abe? Which worker experienced stronger effects on alertness and mood, John or Abe? Which worker experienced weaker effects on alertness and mood, John or Abe? Which worker was exposed to less light pollution, John or Abe? Which worker was exposed to more light pollution, John or Abe? Which worker was influenced less by improper spectral composition, John or Abe? Which worker was influenced more by improper spectral composition, John or Abe?