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]
A couple met at a cafe to discuss their work weeks. Amy had to spend all day inside a brightly lit room to answer customer's complaints. Bob had to work inside a dimly lit cave to shovel coal. They both enjoyed their steak dinners.
Who is likely to have higher worker fatigue: Amy or Bob?