Spectral modulation of light wavelengths using optical filters: effect on melatonin secretion  Robert F. Casper, M.D., Shadab Rahman, Ph.D.  Fertility and Sterility  Volume 102, Issue 2, Pages 336-338 (August 2014) DOI: 10.1016/j.fertnstert.2014.06.006 Copyright © 2014 American Society for Reproductive Medicine Terms and Conditions

Figure 1 Saliva melatonin levels measured every 2 hours from 2000 to 0800 in 13 subjects. On 5 consecutive nights, at least 1 week apart, subjects were exposed to: dark control (<5 lux), light (fluorescent ∼800 lux); placebo (fluorescent light ∼800 lux while wearing glasses containing colored filters that transmitted >50% of all light wavelengths below 500 nm); filter (480 nm; fluorescent light ∼800 lux while wearing glasses containing optical filters that blocked all light wavelengths below 480 nm); or filter (460 nm; fluorescent light ∼800 lux while wearing glasses containing optical filters that blocked all light wavelengths below 460 nm). Figure based on Rahman et al. (14). Fertility and Sterility 2014 102, 336-338DOI: (10.1016/j.fertnstert.2014.06.006) Copyright © 2014 American Society for Reproductive Medicine Terms and Conditions