The eye is a photoreceptor that detects changes in visible light. When light stimulates the rods in the back of your eye a nerve impulse is sent to the brain along the optic nerve, your brain then interprets these impulses to make a picture.
- Ciliary muscles – Contract or relax to alter the shape of the lens (to focus)
- Cornea – Transparent cover allows light in and does most of the bending of light.
- Iris – Alters pupil size (to vary light intake)
- Vitreous Humour – Clear jelly that gives the eye ball shape
- Lens – changes shape to focus light on the retina
- Retina – Contains the light-sensitive receptor cells which change light into electrical impulses
- Rods – sensitive in dim light but only sense black and white
- Cones – sensitive in bright light and can detect colours
- Sclera – Protective tough outer layer of the eye
- Suspensory ligaments – Hold the lens in place
- Optic nerve – Carries the electrical impulses to the brain
The Gif below shows the human eye dilating due to a change in light intake this is controlled by the Iris