The Human Eye

9SCIE - Radiation and the Human Body

Finn Le Sueur

2024

Ngā Whāinga Ako

  • I can annotate a diagram to show how rays of light enter our eyes
  • I can label the main structures of the eye and explain how the structure enables us to see

Write the date and nga whāinga ako in your book

Structure of the Eye

  1. Glue in your diagram of the eye
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Structure Function
Cornea Refracts light, bends it as it enters the eye
Iris Controls how much light enters the pupil
Lens Further refracts light to focus it onto the retina
Retina Converts light energy into electrical energy
Optic Nerve Carries electrical impulses to the brain
Pupil Lets light into the eye

How do we See?

  1. Light hits the cornea and bends towards the pupil
  2. The iris regulates the size of the pupil to control the amount of light that enters the eye.
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Continued

  1. The light passes through the lens which focuses the light onto the retina at the back of the eye
  2. The cells of the retina convert light into electrical signals that travel down the optic nerve to the brain
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Sketch the light rays onto your diagram.

The Role of Refraction

Light rays bend (refract) as they travel through the cornea and lens. This lets the light pass through the pupil and focuses the light on the retina at the back of the eye.

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