For the second time in a year, the Lighting Research Center implicates light levels and duration as greater villains than blue frequencies in poor sleep, reports LEDs Magazine.

“Both amount and spectrum are important, but the impact of amount [of light] on melatonin suppression is greater than that of spectrum,” Figueiro told LEDs. “One cannot dissociate these two parameters. Blue light does suppress melatonin, but the key finding is that it is not just about blue light. If enough energy is emitted at other parts of the spectrum, we will see a response because the circadian system uses all types of photoreceptors to respond to light for melatonin suppression.”