How does the human eye work?
The HUMAN EYE works in a manner similar to a camera: they both focus light rays, and if the light being conveyed is not focused, neither of them can produce a clear vision.
There’s a thin transparent layer that the light passes through when it enters the eye. This layer, known as the cornea, is the lens that focuses the light. Thinking of the eye as a camera, the cornea is a sort of lens cover, and therefore its main job is to protect the front part of the eye, i.e. the iris and the pupils.
Apart from the cornea, the eye features another lens, called crystalline, responsible for focusing the light in order to produce a clear image in the retina, the inner layer of the eyeball located along the back hedge of the eye. The retina of the eye is made of sensory neurons whose main job is to convert the image into signals and transmit it to the brain via the optic nerve.
The signals transmitted by the optic nerve are interpreted as light by the brain, which will reverse the image filling in the blind spot when needed. This is basically the image that we see with our eyes as perceived by our brain.
Structure of the human eye
There are two main structures that protect the eye: the eyelids and the tears.
The eyelid is what protects the eye from damage caused by foreign bodies. Its skin is the thinnest of the human body, and its opening and closing is controlled by the oculomotor nerve, as well as by the orbicularis oculi muscle. Also, the eyelid sweeps the secretions of the lacrimal apparatus over the eye surface to keep the cornea moist.
The tears are produced by the lacrimal system together with other protective fluids in order to lubricate the eye and keep the cornea nourished and hydrated. Tears excess are drained from the eye into the nose, where they keep the nasal linings moist.
To know more about the different parts that form the complicated structure of the human eye, click on the specific terms listed on our glossary page.