now that we know a little bit about the anatomy of the eye our next learning objective is to describe the pathway of light through the eye we see because light passes through the eye is absorbed by photo receptors and is turned into a neural impulse or signal that gets passed back to the brain so starting up here outside the eye and the light first passes through the cornea which is remember that clear part at the front of the eye the light then passes through the anterior cavity which is filled with aquous humor through the pupil which is the hole in the middle of the Aris through the lens which is where the pathway of light can actually be altered a little through the posterior cavity which is filled with vitous humor and then onto this yellow layer here which is our retina so we have corna anterior cavity filled with aquous humor pupil lens posterior cavity filled with Vitus humor and then on to our retina now where it gets a little bit tricky is that our retina is actually made up of a few levels of nerve cells and the light travels in a bit of a funny way so I just wanted to show you that here so if you imagine the light is coming from this direction and moving towards the opposite side of the screen so if this is our posterior cavity here the light actually passes past all of these layers of cells to hit the back of the reer and be absorbed by this layer here so this layer here we call the retinal pigment epithelium and the retin pigment epithelium contains melanin which is a pigment which absorbs and filters light from there the light is absorbed by our photo receptance which are either rods or cones and it's here that the light turns into a neural signal and this message gets transmitted back along bipolar cells into gangan cells and then the axons of our gangan cells form our optic nerve nerve which takes the neural message back to the brain so the light goes through our posterior cavity past all of these cells to our retinal epithelium the lights absorbed by our photo receptors and transmitted into a neural signal which then moves along our bipolar cells into our gangan cells and into our optic nerve