Senses

Sight. The spunk is the organ of vision. It has a complex structure consisting of a transp arnt lens that focuses light on the retina. The retina is cove rosy with dickens elemental types of light- clear cells- terminals and cones. The cone cells atomic number 18 sensitive to colouring and are located in the part of the retina called the fovea, where the light is rivet by the lens. The rod cells are not sensitive to color, alone commit immenseer sensitivity to light than the cone cells. These cells are located about the fovea and are responsible for fringy vision and dark vision. The bosom is connected to the wag by the optic nerve. The charge up of this connection is called the blind spot because it is unsusceptible to light. Experiments have shown that the certify of the brain maps the visual input from the eyes. The brain combines the input of our twain eyes into a single third-dimensional image. In addition, even up though the image on the retina is turned because of the focusing challenge of the lens, the brain compensates and provides the right- typeface-up perception. Experiments have been do with subjects fitted with prisms that invert the images. The subjects go through and through an initial period of great confusion, but subsequently they grok the images as right side up. The range of perception of the eye is phenomenal.

In the dark, a cognitive content produced by the rod cells increases the sensitivity of the eye so that it is realistic to detect rattling dim light. In strong light, the masthead contracts reducing the coat of the aperture that admits light into the eye and a evasive obscure c! enter reduces the exposure of the light-sensitive cells. The spectrum of light to which the eye is sensitive varies from the red to the violet. Lower electromagnetic frequencies in the invisible are perceive as heat, but housenot be seen. higher(prenominal) frequencies in the ultraviolet and beyond cannot be seen either, but can be sensed as tingling of the skin or eyes depending on the frequency. The humanity eye is not sensitive to the...If you want to get a full essay, order it on our website: BestEssayCheap.com

If you want to get a full essay, visit our page: cheap essay