The corneaâs refractive power bends the light rays in such a way that they pass freely through the pupil the opening in the center of the iris through which light enters the eye. The iris works like a shutter in a camera. It has the ability to enlarge and shrink, depending on how much light is entering the eye.ight rays pass through a dense, transparent gel-like substance, called the vitreous that fills the globe of the eyeball and helps the eye hold its spherical shape. In a normal eye, the light rays come to a sharp focusing point on the retina. The retina functions much like the film in a camera.
There are 720 ways in which six things can be arranged. The number of ways that a set of things can be arranged is known as the number of permutations of that set. Each distinct arrangement is called a permutation.
Say you have a certain number of things or objects. They can be numbers, letters, people, colors, etc. In how many different ways can these things be arranged in a row? A permutation of some number of objects means the collection of all possible arrangements of those objects. Enter your objects (or the names of them), one per line in the box below, then click Show me! to see how many ways they can be arranged, and what those arrangements are. Note: 8 items have a total of 40,320 different combinations. For the sake of output and server capacity, we cannot let you enter more than 8 items!