Vision & Light Path Simulator

Watch light leave an object, enter the eye, bend through the cornea and lens, form an inverted image on the retina, and travel as electrical signals through the optic nerve to visual areas of the brain.

Educational model. The geometry is simplified so the optical pathway is easy to see. Real perception is more complex: the brain does not simply “flip a picture.” The cornea provides most of the eye’s refraction, the lens fine-tunes focus, retinal circuits encode visual information, and signals pass through the optic nerve and central visual pathways before reaching visual cortex.

Normal Vision

Light from each point on the object spreads in many directions. The cornea and lens bend some of those rays so they converge on corresponding points on the retina.
Focus: on retina
incoming lightfocused raysretinaoptic nerve signal
1. ObjectLight reflects from scene
2. CorneaLargest refraction step
3. PupilIris controls light amount
4. LensFine focus / accommodation
5. RetinaPhotoreceptors transduce light
6. BrainVisual processing builds perception
Retinal processingPhotoreceptors do not send a tiny picture straight to the brain. Rods and cones convert light to electrical signals, which are processed by retinal circuits before ganglion-cell axons form the optic nerve.
CorneaThe transparent front surface provides most of the eye's optical focusing power.
Iris & pupilThe iris changes pupil diameter, regulating how much light reaches the retina.
LensThe lens changes shape to adjust focus, especially for near objects.
RetinaRods and cones convert photons into neural signals; downstream retinal cells begin processing contrast and spatial information.

Image formed on the retina

The optical image on the retina is inverted and left-right reversed. Photoreceptors respond to this pattern rather than sending a literal picture to the brain.

What you consciously perceive

The visual system reconstructs spatial relationships from retinal signals. Perception is the result of neural processing across the retina, thalamus, and visual cortex—not a simple mechanical image flip.