Exposure to light suppresses the production of melatonin, making it more difficult to fall asleep. A sleep researcher writes for Harvard Business Review about the potential of blue light blocking glasses.
The first study examined 63 managers, and the second study examined 67 customer service representatives. Both studies used the same research design: The employees spent one week wearing blue light filtering glasses for two hours before bedtime each night for a week. The same employees also spent one week wearing “sham” glasses for two hours before bedtime each night. The sham glasses had the same frames, but the lenses did not filter out blue light. Participants had no reason to believe that there would be differential effects of the two sets of glasses on sleep or performance, or in which direction such an effect would occur. We randomly determined whether any given participant spent the first week using the blue light filtering glasses or the sham glasses.
The results were remarkably consistent across the two studies. Compared to the week in which people wore the sham glasses, in the week in which people wore the blue-light-filtering glasses participants reported sleeping more (5% longer in the managers study, and 6% longer in the customer service representative study) and getting higher quality sleep (14% better in the managers study, and 11% better in the customer service representative study).
Sleep quantity and quality both had beneficial effects on all four work outcomes. Compared to the week in which participants wore the sham glasses, in the week in which people wore the blue light filtering glasses, participants reported higher work engagement (8.51% higher in the managers study and 8.25% higher in the customer service representative study), more helping behavior (17.29% and 17.82% more in each study, respectively), and fewer negative work behaviors (11.78% and 11.76% fewer, respectively).