Your eyes, a behind the scenes look.

Your eyes, a behind the scenes look.

The workings of your eyes are both simple and complicated at the same time, this sounds like a contradiction in terms but read on.

Complicated , because there are such a lot of parts that have to work in cooperation to make sight possible. Straightforward , because those parts and the method can truly be explained without detailed awareness of anatomy and biology. An standard glass lens,eg a magnifying glass, focuses the light that moves thru it by bending the rays toward a focal point. That is the bright spot you see when you hold one over a paper, as an example.

Something similar takes place when light enters the eye thru an opening called the pupil, behind a clear protecting portion called the cornea. The pupil is encircled by the iris, the colored portion of the eye. The pupil can narrow or widen to control the quantity of light admitted, from as tiny as about 2mm to as much as roughly 8mm. Just behind the pupil is the lens, the part that focuses the light rays like the magnifying glass. The magnifying glass's focal point is fixed. The eye, against this, contains muscles that help shape the lens and that shaping process performs some significant jobs. As the camera lens contains multiple pieces of glass that may be moved by turning the barrel, objects at different distances can be brought into target the film. The muscles attached to the lens perform a similar function to focus light onto the retina, which is the same as the film.

Targeted light rays strike the cells of the retina, the cones and rods. The names come from the shapes of the cells. The roughly one hundred million rods around them help us see in dim light and supply marginal vision. When those centered light rays hit the cells chemical reactions happen that excite the optic nerve attached to the back of the retina to supply electric impulses. Those impulses are then broadcast to the visible cortex, the part of the brain that organizes them. Plenty of parts of the brain cooperate to cause the mind to conclude : 'Ah, a car.' But the visible cortex will the first heavy lifting. When the parts and process of vision work properly, you see pointy, colored entities out around the planet.