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
Colour centre colour blindness, as well as the idea that there are area specializations in the cortex. Many studies have shown that lesions in the areas commonly identified as the colour centre, such as V1, V2, and the V4-complex lead to achromatopsia. Cerebral achromatopsia occurs after injury to the lingual or fusiform gyrus, the areas associated with hV4. These injuries include physical trauma, stroke, and tumour growth. One of the primary initiatives to locating the colour centre in the visual cortex is to discover the cause and a possible treatment of cerebral achromatopsia. The extent of the symptoms and the damage is