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 eye". It is a common problem experienced by people of all ages. Related eye symptoms and signs of irritation are discomfort, dryness, excess tearing, itching, grating, foreign body sensation, ocular fatigue, pain, scratchiness, soreness, redness, swollen eyelids, and tiredness, etc. These eye symptoms are reported with intensities from mild to severe. It has been suggested that these eye symptoms are related to different causal mechanisms, and symptoms are related to the particular ocular anatomy involved. Several suspected causal factors in our environment have been studied so far. One hypothesis is that indoor air pollution may cause eye and airway irritation.