What happens to light after it enters our eyes? Do photons just bounce around in our brains forever?


What the photons doin?

In: 6

They are absorbed by the rods and cones of the retina (the black “screen” at the back of the eye) where their energy triggers electrical signals to the brain.

A few photons stimulate a rod or cone cell which generates a neural impulse that travels along the optic nerve to your visual cortex. In the process of stimulating the retinal cell, the photon changes frequency to the infrared spectrum, becoming heat.

Light does occassionally bounce around our bodies but not the light we perceive with eyes. That light was converted from an electromagnetic wave into an electrochemical reaction on the surface of a rod/cone cell.

Radio waves pass through us constantly, and they are pretty much everywhere on earth with electronics. When traveling by airplane, we are exposed to an increase in X-ray waves. UV waves from the sun come through in larger ratio near the equator; they can be absorbed and potentially damage us, pass through us and miss us, or bounce off our tan or sunscreen. Light at most frequencies can pass through us if it happens to intersect us, with visible light being an obvious exception to the rule.