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Today we know that optimizing daylight as a light source in school buildings improves students’ academic performance. Sunlight drives natural circadian rhythms of hormones, organs, tissues, and the sleep-wake cycle by working with—rather than against—the body’s natural circadian rhythm.

The new WELL Building Standard for daylighting is designed to reinforce a normal circadian rhythm and improve visual acuity. To enhance students’ cognitive functions, sustainability officers and architects should provide illuminance recommendations that maximize natural daylight.

Key Facts

  • In the district with the most detailed data, it was found that the students with the most daylight in their classrooms progressed 20% faster on math tests and 26% faster on reading tests in one year than those with the least. Similarly, students in classrooms with the largest window areas were found to progress 15% faster in math and 23% faster in reading than those with the least.
  • Our circadian rhythm operates on a 24-hour cycle that controls our physiology—not only sleep and wakefulness but many physical, mental and behavioral functions as well: blood pressure, heart rate, alertness, body temperature and reaction time.
  • ipRGCs are most sensitive to light at the short wavelength of between 446nm and 477nm (cyan). Short-wavelength light increases alertness by suppressing melatonin production.