Evolution of human colour vision opsins was increasing from 400 to 430. During this time, Ancestral Boreotherian had two long wave length opsins created by gene duplication, with one retaining the absolute max value of 560, equal to the ancestral value. This led to the creation of the modern human long wavelength sensitive, or red opsin. The other short wavelength sensitive opsin decreased its absolute max value to 530 and became the middle wavelength sensitive, or green-sensitive opsin. This occurred through mutations involving S180A, Y277F and T285A. The order that these mutations took place in the ancestral Boreotheria is currently not fully known. It is
Human eye hampered by retinal disease, poor vascular circulation and high altitude exposure. The human eye can detect a luminance range of 10, or one hundred trillion (100,000,000,000,000) (about 46.5 f-stops), from 10 cd/m, or one millionth (0.000001) of a candela per square meter to 10 cd/m or one hundred million (100,000,000) candelas per square meter. This range does not include looking at the midday sun (10 cd/m) or lightning discharge. At the low end of the range is the absolute threshold of vision for a steady light across a wide field of view, about 10 cd/m2 (0.000001 candela per square meter).