Light refraction is the key to how the eye creates vision. Light enters the eye through the cornea, which acts as a clear, protective outer covering. The cornea bends or ‘refracts’ the light towards the pupil, which is the black circular opening in the center of the iris.

The iris is the colored part of the eye, which adjusts the size of the pupil to regulate the amount of light entering the eye. In bright conditions, it contracts to reduce the pupil size which restricts too much light from entering the eye, and in dim conditions, it dilates to increase the pupil size which allows more light in, giving you better vision when it’s dark out.

Beyond the pupil lies the lens which is a flexible, transparent structure that further refracts light to focus it precisely onto the retina. Muscles attached to the lens can change its shape

Light focused by the cornea and lens forms an inverted image on the retina. Once the brain receives the image, it automatically inverts it again so that we see things correctly.

The retina lines the inner surface at the back of the eye and contains millions of photoreceptor cells called rods and cones that convert light into electrical signals.

Rods and cones contain light-sensitive pigments (like rhodopsin in rods and opsins in cones) that change shape when exposed to light. This change triggers a cascade of chemical and electrical signals, ultimately generating nerve impulses that travel to the brain for interpretation.

how the human eyes are placed in the skull allows for binocular vision. This is where each eye sees a slightly different image. This disparity helps with depth perception and spatial awareness.