“…In an effort to standardize these light measurements, the Commission Internationale de l'Eclairage (CIE) specified the use of a specific light source (Source C) and a response curve based on a standard observer. Source C refers to a light with spectral characteristics of average daylight and is generated by an incandescent lamp operated at a color temperature of 6800 K. 3 The human eye responds to light over the energy wavelength region of 380 to 770 nm. However, the human eye has a maximum response to green light at about 550 nm.…”