A study very fancy titled “Attenuation of short wavelengths alters sleep and the ipRGC pupil response” was recently (June 2017) published in OPO.
Luckily, the practical applications of said study are more down to earth: In short, participants were asked to wear blue-light blocking glasses every night before bedtime for 2 weeks. Night-time melatonin-concentration, sleep duration and sleep quality were measured. Subjects wore the glasses 3:57 ±1:03h each night.
Night time melatonin increased from 16.1 ± 7.5 pg mL−1 to 25.5 ± 10.7 pg mL−1 (P < 0.01). Objectively measured sleep duration increased 24 min, from 408.7 ± 44.9 to 431.5 ± 42.9 min (P < 0.001). Mean PSQI score [measures sleep quality] improved from 5.6 ± 2.9 to 3.0 ± 2.2.
Less blue-light before bedtime; better and longer sleep. Good stuff.