Why is the visual image projected on the retina of the human eye upside down?

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Diagram of a horizontal section of the human eye showing labeled parts including the cornea, iris, lens, retina, sclera, optic nerve, and blood vessels, with internal structures and muscles visible. — human eye A horizontal cross section of the human eye, showing the major parts of the eye, including the protective covering of the cornea over the front of the eye.

The visual image projected onto the retina of the human eye is upside down because of how light rays are refracted by the eye's optical system. The cornea and the lens work together as a convex lens, bending light rays to converge. This process results in an inverted image being formed on the retina. The retina then converts this light into chemical energy, which activates nerves that transmit visual signals to the brain for interpretation. The brain then corrects this inverted image, allowing us to perceive the world upright.123