(1) The lens works much like a camera, focusing light onto the retina at the back of the eye.(2) As with similar work in the United States, the prosthetic retina works by passing artificially stimulating the optic nerve, in line with signals from a tiny digital camera mounted on a pair of glasses.(3) His dissection of the eye yielded the distinction between cornea, retina , iris, and chorioid coat.(4) The protein of the lens had changed, making it opaque and preventing light from reaching the retina .(5) Seeing an object requires the mediation of light to create an image in the retina .(6) More than 10 million Americans are thought to have macular degeneration and retinitis pigmentosa, diseases of the retina that often result in blindness.(7) The chip captures light that enters the eye, and generates an electrical signal that is transmitted to the overlaying neural cells of the retina .(8) The flatter cornea then focuses images farther back inside the eyeball, projecting them on the retina instead of in front of it, as is the case in nearsightedness.(9) I watched until my eyes hurt, and when I turned away, a black imprint was left on my retina by light too strong to bear.(10) And for vision it is also necessary that there should be visual purple behind the retina and an opaque cornea and iris.(11) Light rays bounce off the person and onto the retina through the pupil, so if the pupils are large, more light will enter the eyes, and therefore providing a better image.(12) He tried to imagine a world with colours and brightness but all he could think of was the feeling he got when he stared directly at a light for too long and it burned a red and blue image on his retina when he closed his eyes.(13) In Steven Spielberg's film, Minority Report, every time Tom Cruise walked down a street, advertising billboards scanned his retinas and broadcast personalised ads.(14) Lutein is one of the hydroxy carotenoids that make up the macular pigment of human retinas .(15) However, in 1996, scientists at the University of Illinois in Chicago found that astaxanthin protected the retinas of rats exposed to damaging light.(16) Many people with total blindness experience life-long sleeping problems because their retinas are unable to detect light.