If we compare the eye to a camera, then the eye is a very sophisticated camera, with two aspheric lenses, the cornea and the lens, hidden under the lid of the eyelid, which opens and closes as usual. The cornea is at the front of the eye, protecting the eye and playing the role of a fixed-focus lens; the lens is inside the eye, hiding behind the pupil (equivalent to an aperture) that can stretch freely and play the role of a zoom lens. Unlike a camera, the two lenses of the eye have to work together and focus collaboratively in order to take in everything in sight.
Speaking of the fundus, let’s understand the vast space between the lens and the fundus. This space is filled by a collagen fiber hydrate called vitreous humor, which is semi-solid and has a structure somewhat like a transparent jelly. The role of this vitreous body in the eye is, simply understood, to fill the eye, cushion the shock, and support the retina.
Now let’s go to the very back of the eye and take a peek. The last side is the fundus of the eye, there is a fine structure called the retina, the normal retina is like the best imaging quality camera negative, eyelids blink between, the wonderful collection of retina.
Behind the eye trails a thin optic nerve, which is so important that it acts as a data line for a digital camera, transmitting the information collected by the retina to the workstation in the cerebral cortex.
The precise window of the mind needs to be well protected.