Functions of the eye

• The eye is a sense organ that contains receptors sensitive to both light intensity and the colour of light
• The transparent front of the eye is called the cornea

  • Light rays pass through the cornea
  • The job of the cornea is to start the focusing of the light rays
• The pupil is in the center of the iris

  • The iris is the colored part of the eye
• Light passes through the cornea, then the pupil, then the lens

  • The job of the lens is to focus the eye rays onto the back of the eye
• The lens can change its shape, allowing you to focus on distant or near objects. This process is called accommodation
• The retina is at the back of the eye

  • The retina contains receptor cells for light, and allows us to detect light intensity and light color
  • The receptor cells in the retina send electrical impulses down the optic nerve to the brain
• The white part of the eye is called the sclera. It is a tough outer structure that protects the eye
• The ciliary muscle and suspensory ligaments work with the lens to allow us to focus on distant or near objects
• The pupil is the space in the center of the iris which light passes through

  • The iris controls the size of the pupil
• Light intensity is sensed by light receptors in the retina and sends electrical impulses to the brain

  • The brain sends electrical impulses to specific muscles in the iris
  • The muscles in the eye contract causing the pupils to become larger to allow more light to enter into the eye
  • The pupil shrinks to reduce the amount of light entering the eye and protect it from damage