大象传媒

This clip is a look at the human eye and how it works. We illustrate the functions of the eye with models, film clips and magnified images. The eye is a ball with a hole at the front, the pupil, which lets in light. Inside the eye is a lens which focuses the light onto a surface at the back of the eyeball. This surface is called the retina and is made up of special cells which detect light and send messages to our brain, allowing us to see. When we have our eyes tested, an optician shines a light into our eye and uses a magnifying lens. This shows the optician the blood vessels on the surface of the retina and the light-sensitive cells. A human eye has more than a million light-sensitive cells.