Why does the nasal half of the retina see the outer half of the world? · Grey Matter

The cornea and lens act like a camera lens and project an inverted, reversed image onto the retina.

Why does the nasal half of the retina see the outer half of the world?

The cornea and lens act like a camera lens and project an inverted, reversed image onto the retina. Light from an object far out to the side enters the pupil at an angle and lands on the opposite part of the retina, which is the half nearest the nose. The nasal retina therefore serves the temporal field, and since its fibres are the ones that cross at the chiasm, damage at the crossing removes the outer field of each eye.