To realize the outer world our body has been provided with five sense organs (Jnanendriayan). Eyes are one of the sense organ whose proper functioning of the eyes is very important for visually perceiving the world around us. Eyes provide us the ability to process visual details of the objects around us, in addition to enable photo response functions not depending on vision. Defect free functioning of eye is very important in sensing the world around us for performing dutiful action (Karmyoga). Visual system is a complex optical system in which eye collects light from the objects around it, regulates the intensity of light through a diaphragm (pupil), focuses it through an adjustable assembly of lenses to form an image (on retina), converts this image into a set of electrical signals (photoreceptor cell in the form of cones and rods are present on the retina surface convert the optical image to electrochemical signal), and transmits these signals to the visual cortex in brain through optic nerves and neural connections.