Eyes are the most complex, sensitive and impressive organs in a human body. The reason is their ability to perceive the wonderful and amazing three-dimensional world but, how is it possible. It’s obvious we can see objects near and far, differentiate colours and have a sharp perceptive sense which is possible only when brain works in line with the eyes thus giving us the sense of sight.
Working of the Human Eye
When light is bounced off the objects and reaches our eyes, the brain comprehend these waves or rays to identify images. Camera works in the same way as our eyes which you can recall by the pinhole camera experiment; the inverted light rays.
As for the sight, clear and focused image of the outer world depends on the eyes whereas our brain works in recognising the images via visual memory. The first step begins at the cornea as light which is bounced off the objects is directed to the retina where it refracts and bends through the pupil; the black centre-point in the eye.
Eye pupil expands and contracts based on intensity of the light, colour and everything which it processes before sending the signal to the brain. This is where the iris comes into play which is the coloured area of the eye that calibrates the amount of light coming in. Take for instance a darker surrounding where the iris expands to take maximum light for better visibility.
It then travel through the lens which is flexible part where the light ray is bent once again to enhance the focus before it is sent to the retina, located at the back or posterior of the eye. This way, a human eye is capable to capture or digest the entire scene/picture which is then ready to be edited.
This visual editing occurs on the back of the eye, from the retina which is a thin tissue containing cells known as photoreceptors that are of two types namely rods and cones. The photoreceptors are found in concentration at the area known as the fovea aka central vision. Due to the high concentration, this is the point where maximum sharpness of the image is defined.
Images that are farther from the fovea appears blurry and less sharp however visible which is termed as peripheral vision. Once image is being received by the rods and cones, they’re transformed into electrical impulses that are sent to the brain via optic nerve.
The Brain Game
Passing through the optic nerve and the cerebral cortex located at the root of the brain, the electrical impulses officially leave the eye and arranged at two different regions of the brain. A group of cells known as pretectum and the other one is the nucleus also known as superior colliculus.
Both of the regions interprets the impulses and form the image as it is in real. Projections from the retina are transmitted to the lateral geniculate nucleus located deep in the brain where the image is further divided per its colour, structure, contrast and motion after which it is processed and thus give us the final 3D cut of the picture.
To keep the eyes performing at their optimum and to enjoy 3D movies, use prescribed eye drops for dry eyes and other such symptoms.
