Patent ID: 8164844

Claim:
An optical filter, the optical filter comprising: an optical filter means for preventing melatonin suppression, wherein a mean transmissivity of the optical filter for light having a wavelength of about 480-505 nm passing through the optical filter is about 30% or less, wherein a mean transmissivity of the optical filter for light having a wavelength of about 380-440 nm passing through the optical filter is about 50% or more, wherein a mean transmissivity of the optical filter for light having a wavelength of about 430-445 nm passing through the optical filter is about 50% or less, wherein a mean transmissivity of the optical filter for light having a wavelength of about 530-565 nm passing through the optical filter is between about 45% and about 75%, and wherein a mean transmissivity in a wavelength range of about 400-440 nm is greater than about 30%.