Sight - key words

Iris - Coloured circle around the pupil. It controls the size of the pupil

Pupil - Black part of the eye. This is an opening that lets light in

Lens - This focuses light onto the retina

Retina - Light-sensitive layer at the back of the eye. It is made up of rods and cones

Rods - Sense cells that help us see the shapes of things

Cones - Sense cells that help us see colours

Optic nerve - Carries messages from the retina to the brain. The brain turns these into an image of what we are looking at