- Blue light plays a larger role in scotopic sensitivity than violet light.
- Blue-light blocking may compromise low-light vision by reducing the amount of useful light reaching the retina.
- Blue light also plays a larger role in photoentrainment of circadian rhythms than violet light.
- Retinal ganglion cells, which control the secretion and suppression of melatonin, contain a photopigment called melanopsin, which has peak spectral absorption in the blue region.
- Blue-light blocking may affect the regulation of circadian rhythms.2
Reference:
2. Cajochen C, Jud C, Munch M, et al. Evening exposure to blue light stimulates the expression of the clock gene PER2 in humans. Eur J Neurosci. 2006;23(4):1082-6.