Lens

Lens are defined as a piece of transparent material that is designed to take in parallel photons. Many people may think of contact lens that individuals, who are farsighted, might wear as a correction for their vision. Contact lens correct farsightedness by converging light rays and increase the eye’s ability to focus. Converging lens are thicker at the middle while diverging lens are thicker at the edges and both types exist depending on what the lens is trying to correct. Since contact lenses rest directly on the eye, they are much thinner than eyeglass lenses that otherwise need to be resistant. They are also shaped to be thin and flexible to fit comfortably on the cornea of the eye. Lastly, lenses are also made to be gas-permeable to allow oxygen to reach the cornea. This explains, why contact lenses are not recommended to wear over a long period of time and advised to wear glasses once in a while to allow the eyes to ‘breathe’.