Formation of an Image on the Retina.
In the same manner that a glass lens can focus an image on a sheet of paper,
the lens system of the eye can focus an image on the
retina.The image is inverted and reversed with respect
to the object. However, the mind perceives objects in
the upright position despite the upside-down orientation
on the retina because the brain is trained to consider
an inverted image as the normal.