No audio description: http://www.nlm.nih.gov/medlineplus/ency/videos/mov/200067.mov
OverviewAs light enters the eye, it strikes the receptor cells of the retina called the rods and cones. A chemical reaction results in the formation of electric impulses, which then travel to the brain through the optic nerve.
Update Date 12/6/2012
Updated by: Paul B. Griggs, MD, Department of Ophthalmology, Virginia Mason Medical Center, Seattle, WA. Review provided by VeriMed Healthcare Network.