Sleep Quality of Youth (Part 2.1 of a 7 Part Series)

Sleep Quality of Youth (Part 2.1 of a 7 Part Series)

Welcome to part 2.1 of the Healthy Lighting series, where we explore implications of light on the health of human beings. Today we re-investigate the importance of quality sleep for our youth and the role that light plays in it.



Light triggers critical physiological and psychological responses within human beings. The level and quality of light within the built environment has real implications on our health and wellness as we become more aware of light’s implications on our health, we have a larger repertoire with which to impact a positive benefit on our health.



  • During the spring, late sunset and extended daylight exposure delays bedtime in teenagers.

  • Increased exposure to early evening light delays the onset of nocturnal melatonin.

  • Nocturnal melatonin: hormone that indicates to the body when it’s nighttime.

  • Combine the delay in sleep with early school hours means many teens experience sleep deprivation, mood changes, increased risk of obesity and under performance at school.

LRC Case Study at Algonquin Middle School

  • 16 students were given a daysimeter – a small device to measure an individual’s exposure to daily “circadian light”.

  • Circadian light: the potential for light to suppress melatonin synthesis at night not how light stimulates the visual system.

  • Experienced a delay in melatonin onset by an average 20 minutes in the spring relative to winter.


  • Extended daylight hours due to the seasonal change, not evening electric lighting, had the biggest impact on delayed sleeping patterns.

  • The melatonin delay caused an average of 16 minute delay in reported sleep onset and a 15 minute average reduction in reported sleep duration during the spring.

  • The Lighting Research Center (LRC) recommends that teenagers increase morning daylight exposure throughout the year and decrease evening daylight exposure during the spring months.


Look out for 2.2 of this 7 part series, where we explore lighting for the elderly!