Iris – a diaphragm that regulates amount of light by expanding contracting also know as (Pupil), lens that focuses under the control of ciliary muscles forms image on to the retina. The lens is crystalline in nature. Lastly there is a screen like structure called retina that is holding a lot of - optic nerves – that communicate with the brain. The central region has the greatest sensitivity and is called Fovea. Fovea is the most acute spot of vision where fine details are formed. Rest of the retina is responsible for orientation. The eye communicates through optic nerves located on the retina. They are a system of double nerves called Rods and Cones. Rods are responsible for Dim light / Night vision and Cones are mainly concentrated around or at Fovea and are responsible for form/color sensitivity.