Evolution of human colour vision that are found between 450 and 625. Individuals with various forms of colour blindness such as deuteranopia and protanopia are missing human middle wavelength sensitive or long wavelength sensitive opsins. Their minimum wavelength differences are <5 but only at around 500. Protanopes, who are missing long wavelength sensitive cones, are unable to distinguish between colours in the green-yellow-red section of the electromagnetic spectrum. They find yellow, red and orange colours to have much lower brightness when compared to a trichromat. The dimming of these colours can result in confusion in many cases, such as when attempting to identify red traffic
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).