Eyes are the most important sense organs which allow us to view this colorful world. We use our eyes to distinguish different colors and lights, change these visions and images into neural signals and finally transmit them to brain. A saying that “eyes are the soul windows” obviously reveals the importance of eyes. However, people will not notice the importance of eyes until one day they loss the vision. Eyes are quite vulnerable to many disorders like dryness, itching, pink eye, cataract, glaucoma, myopia, hypermetropia and etc. Most people will experience at least one of them during their life or get other temporary eye problems from time to time. Most of this eye disorders are short-lived will probably go away on their own. However, those eye problems that last for more than a couple of days will develop to serious eye disorders if left untreated. There are314 million people are visually impaired among which 45 million are blind, 124 million have low vision and 145 million have unc...