What Do You See?
Bears can see fairly well, at least as well as humans. Their eyes are small, round, widely spaced, and forward facing. Bears color vision is especially sensitive to blue, green and red wavelengths. Similar to the same color vision that humans have. The ability to see colors probably helps bears find food, since much of their diet consists of colored berries and fruits. Bears have good binocular vision that allows for good depth perception. However, they are nearsighted, and have difficulty distinguishing objects at a distance.
Vision is the most important sense for all birds, since good eyesight is essential for safe flight. Birds also have the ability to see not only the visible color range but also the ultraviolet part of the spectrum, and can detect polarized light and magnetic fields.
Pigeons can see millions of different colors and are thought to be among the best at color detection of any animal on earth.
Ducks can see well both in air and water. In air a ducks eye is similar to a human eye, where the cornea focuses the light and also having a flat lens. However, when a duck is in water the cornea no longer focuses light, it pushes against the iris forming a bulge on the front surface of the lens. This bulge acts as a very powerful lens allowing the duck to see underwater.
Horses have an amazing range of vision – that is, except for what is right in front of them. They literally cannot spot whatever is between their eyes and and can only see what is directly ahead due to their binocular vision.
Frogs have very good eyesight, as they need this in order to obtain food. A common misconception is that frogs cannot see things that do not move. (If this were the case, they would constantly be jumping into stationary objects). If a prey is not moving, the frog will not snap at it because the snapping behavior is instinctual, only provoked by tiny objects moving.
Cats can see quite well in light levels as little as 1/6 of what is required for humans to see. This is because they have a light-enhancing device at the backs of their retinas called the tapetum lucidum, which means “bright carpet” in Latin. This shiny layer of cells, act like a mirror and reflects light back to the retina's cells.
Probably one of the most frequently asked questions about dog's vision is whether dogs see colors. It has been scientifically confirmed that dogs actually do see color, but many fewer colors than normal humans do. Instead of seeing the colors of the rainbow as humans do, dogs would see it as dark blue, light blue, gray, light yellow, darker yellow (sort of brown), and very dark gray. In other words, dogs see the colors of the world as yellow, blue and gray.
Sheep depend heavily on their vision. They have excellent peripheral vision and can see behind themselves without turning their heads. However, they have poor depth perception. They cannot see immediately in front of their noses. Some vertical vision may also have been sacrificed in order to have a wider field of vision.
Fish see best at close range with eyes that are similar to those of humans. Fish have protective film over their eyes so that they can see clearly underwater. Because water can be cloudy, many fish must use their other senses for finding food and escaping predators. Fish can see the seven colors of the visual spectrum as well as ultraviolet and polarized light.
The color of the objects that we see is due to the way those objects interacts with light. The color of an object is not actually within the object itself. Rather, the color is in the light that shines upon it and is reflected or transmitted to our eyes.
Light enters your eyes, through the pupil and reacts to changing light by changing size. The pupil gets larger to let more light in and smaller in bright sunlight. Behind the pupil, a rubbery membrane called the lens that focuses the light as it passes through. Through the eyes inner chamber, the light strikes a screen called the retina. The retina is lined with millions of light-sensitive nerve cells, some cells are shaped like rods and some cells are shaped like cones. Cone cells let you see color and visual sharpness and rod cells let you see black and white. Rod and cone cells send signals to the brain through the optic nerves and carry the information about the light to your brain.