Vision is the ca ability of some living beings to recognize, to distinguish and to interpret luminous stimuli.

Vision is significant on earth mostly in the terrestrial and in superficial aquatic habitats since our planet is extremely exposed to sunlight and therefore light and colors become distinguishing factors of objects existed in the atmosphere, even at distance. This distinction provided latest survival strategies for the organisms, new protection methods against external dangers, new ways to find food and to communicate with other individuals, new kinds of courting and reproduction behaviors and so on. That is, it made new possibilities of interaction with the surrounds and raised capacity to explore latest ecological niches.