A major cause of common sleep problems like difficulty falling asleep, bad sleep quality, and difficulty waking up is circadian disruption.

Light is the principle Zeitgeber that entrains our biological clock in the brain. Circadian disruption occurs when our exposure to light is too low during the day and too high in the evening. An insufficient daytime light exposure results in too weak a signal to keep our biological clock entrained.
This CPD covers an in-depth look at what sleep is, what circadian rhythms are and light’s entrainment of them, the effect of circadian disruption on sleep and the knock-on negative effects of sleep deprivation on general health.
Connected with the above, shortcomings of common indoor lit environments are discussed, followed by a look at lighting recommendations which can go a long way toward solving these shortcomings.

Moving from the from the academic to the practicable, an integrative (ie looking at visual and non-visual needs) lighting design process is described with a case study as an illustration.