How Different Species Use Their Eyes

Different eyes for different species The Human Eye Human eye can see around 2.7 million different colors "At the blink of an eye" - your eye is the fastest muscle in a human's body The eyeball weighs around 28 grams Flies And Their Eyes Flies are very short sighted (can only see a yard ahead) Flies have no pupils, so they can't control how much light goes into eye - they can't focus Flies have an almost 360° view of the world Day eyes see by movement, so sometimes they ignore still prey Snake's pair of eyes Snakes have 'pits' next to their eyes that sense heat for night vision To substitute for their poor eyesight, they use vibrations for depth perception They can see both forward and to the side at the same time Hawks and Eagles Its sharpness is at least four times that of a person with perfect vision Their eyes have special retinas with O small light sensitive cells that allow them to see small animals Horses Eyes horses see mainly in shades of grey Horses can only see things to the side of their head horses see two images and can not merge them into one like human's binocular vision Fish focus by moving the lens Fish Eyes backwards and forwards Fish are without eyelids as they do not need to maintain moisture Consequently, fish sleep but with their eyes open LensGenie.co.uk http://www.lenstore.co.uk/blog/101-amazing-eye-facts http://animals.pawnation.com/flies-see-out-compound-eye-5361.html http://www.livescience.com/32114-can-snakes-see-well.html http://www.eyes-and-vision.com/how-animals-see-the-world.html- http://www.petalia.com.au