About 77% of all lifeform (mainly insects and crustaceans) see the world through compound eyes, which are composed of several thousand (one direction oriented) smaller eyes (ommatidia). Every individual smaller eye only percieves a limited space, through its own “simple retina and lens“. The entire picture is like a mosaic composed of individual ommatidia pictures. In the Vertebrate Phylum (human being including) as well as a majority of cephalopods (about 5% of animate beings on the whole) we find the most perfect eye apparatus - the vertebrate eye. In contrast to human eye the retina of most birds conteins 4-5 photoreceptors which create a definition of much finer colour differences; that is why „a bird´s world is much more colourful“. The starfish´s eyes are placed at the ends of the “arms”. Some of the scaled reptiles have a small organ called the parietal eye between the parietal bones of their skull. The lens in the parietal eye is sensitive to light and darkness. Bees have two compound eyes and three simple (parietal) eyes on the upper part of their heads. Snakes are able to percieve infrared light, which enables them to view their surroundings like a thermal map. Although cats cannot see in the total darkness, they can see at overcast night, when the sky is obscured by clouds and somewhere stars shine. Some white and red blossoms as well as the green leaves appear achromatic to bees, in grey scale then. The basis of eyesight is light-percieving cell; the earthworm´s body is covered in them which means it can recognize, which part of its body is illuminated. Kestrels search its main prey - field mouses - thanks to their territorial signs, in UV light their urine is brightly yellow. In UV light we can see completely different patterns on parrot feather.