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.
FYI: How Many Different Ways Can a Chess Game Unfold? Almost nothing looks more orderly than chess pieces before a match starts. The first move, however, begins a spiral into chaos. After both players move, 400 possible board setups exist. After the second pair of turns, there are 197,742 possible games, and after three moves, 121 million. At every turn, players chart a progressively more distinctive path, and each game evolves into one that has probably never been played before.