Eyes are organs of the visual system. They provide animals with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and convert it into electro-chemical impulses in neurons. In higher organisms, the eye is a complex optical system which collects light from the surrounding environment, regulates its intensity through a diaphragm, focuses it through an adjustable assembly of lenses to form an image, converts this image into a set of electrical signals, and transmits these signals to the brain through complex neural pathways that connect the eye via the optic nerve to the visual cortex and other areas of the brain.
While most of us know that we need to schedule routine maintenance for our cars and even our heating and A/C systems before they break down rather than waiting for disaster to strike, sometimes we're not quite as conscientious when it comes to our own health and well-being. Sure, we might undergo an annual physical each year, but unless we're complaining of any particular symptoms, such a checkup might not amount to much more than a weigh-in, a stethoscope to the chest, and maybe a hammer to the knee to check if you're still alive and (literally) kicking.
There is no denying that many people love white teeth, on themselves as well as on others. Having white teeth is not only aesthetically appealing to most people but it also has a psychological reason behind it. According to Dr. Dacher Keltner, a professor of psychology at the University of California, Berkeley, most people are attracted to white teeth because they appear to be cleaner and healthier as compared to stained or yellow ones