The Eye

Sclera - The tough, visible, white part of the eye 

Cornea - Lets light into the eye

Iris - Coloured ring of tissue

Pupil - Lets light through => is black because no light is escaping from the inside of the eye

Chloroid - Contains pigment cells that stop light being reflected around inside of the eye

Retina - The place that light energy is transduced to electrical energy of nerve impulses

Distant

• Ciliary muscles relax
• Suspensory ligaments pulled tight
• Lens becomes 'flat'

Nearby

• Ciliary muscles contract
• Suspensory ligaments slack
• Lens becomes rounded

Bright

• Circular muscle contracts
• Radial muscles relax
• Pupil constricts

Dim

• Circular muscles relax
• Radial muscles contract
• Pupil dialates