Eye and sight

The eyes are the sense organs of sight. They detect light so we can see shapes and colours, and estimate distances. We see and look the world around us, but we never stop to think how. Your eyes are almost like a ball. The circle in the centre of your eye is called iris (can have different colours), the small spot in its centre is called the pupil. The pupil is like the window of a room. The iris can open wide or shut narrow the pupil to let just the right amount of light come inside the eye, so when you are in a dark room, your pupil becomes bigger to let more light in. Nevertheless, if you move to a place with more light, the iris will shrink to allow only the required amount of light. This light passes through the cornea and lens to fall onto the retina. The retina is a super sensitive surface with lots of optic nerve endings. These nerves take the upside down image from the retina to the brain, which must first invert it and then make sense of it. The information captured by receptors in the retina travels to the brain through the optic nerve. The brain receives and interprets this information.

The pupil and the lens continuously keep adjusting so that you can see the clearest image of the world. For some people, these adjustments are not enough but these problems can easily be corrected using glasses.

However, all of this is different for aliens. The eyes are the sense organs of smell. They use them to breathe and to detect different smells in the air. Aliens capture the smell by the nosesenotril, which form is really similar to the pupil. The openbig is like the iris, which allows to make the nosesenotril bigger if the alien wants to breathe or smell something in a deeply way. The smell and the air passes through the neaco and the jint until they reach the natire, which is in charge of detecting bad or toxic smells. Moreover, the information captured by the receptors travels to the brain through the noyese nerve. The brain receives and interprets this information.