Vision is our major sense, we have then to educate and control it
Just like a camera (wich is a mechanical copy) the eye is an optical system with
2 "lenses", the Cornea and the Lens, the Iris acting like a diaphragm;
the image come through the Pupil in; at the bottom of the globe lies the Retina
the receptive surface.
Furthermore the shape of the lens may vary, allowing focus.
well then, this retina consist of two kind of photoreceptor cells, cones and rods,
where cones are divided into three kinds of photoreceptors for red, green and blue!
Rods are the luminosity receptive cells.
We already know that it is well enough to distinguish many a colors.
As for all lenses the Lens transmits a reverse picture on the Retina, what doesn't matter by the way because it is not the image itself wich is sent to the brain but a set of spatial and chromatic data which would be integrated at once, the picture beeing rebuilt from this work.