Evolution of human colour vision similar. Tritanopes are missing the short wavelength sensitive opsins and see short wavelength colours in a green hue and dim compared to other colours. They may also see some short wavelength colours as black. Other perception problems include distinguishing yellow from pink or purple colours being perceived as shades of red. Researchers have found that trichromacy has advantages over dichromacy or anomalous trichromacy at further distances. This is believed to occur because visual cues such as shape decrease for colour vision as distance increases for targets of a smaller size. Using tests for spotting fruit pieces in bushes at distances
Evolution of human colour vision hypothesized that T285A was one of the first two mutations because absolute max values would be between 532-538 which is close to the absolute value found in human middle wavelength opsins. Normal human trichromats require a mixture of three primary colours for every day colour vision. Protanopes, deuteranopes and tritanopes are all dichromats, meaning they use a mixture of two primary colours to match any specific colour that they see. Thus, they are missing one of the three wavelength sensitive cones. Trichromats with all three cone pigments intact can generally see minimum wavelength differences between <1 and <3 for wavelengths