Evolution of human colour vision lights, which appear to be clear. Other colour perception issues include having trouble distinguishing yellows from reds and violet, lavender and purple from blue. In other cases, objects that reflect both red and blue light may appear to just be blue to these individuals. Deuteranopes, who are missing medium wavelength sensitive cones, are similar to protanopes in that they cannot distinguish between colours in the green-yellow-red part of the electromagnetic spectrum. However, deuteranopes do not suffer from dimming issues. For example, purple colors are not seen as being opposite to other colours in the spectrum but instead appear to be
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