5.1.5  Retina

The retina is a complex layer of tissue at the back of the eye, where the image from the light entering the eye is focused. When light hits the retina, it send signals to the brain along the optic nerve. The brain interprets these signals and turns them into information about what the eye is seeing. Damage to any of the structures of the eye due to physical injury or infection, or their gradual wearing out due to age, reduces the quality of vision.

Now try this exercise to test your knowledge of the structures of the eye.

  • Look at Figure 5.3. Can you add the correct names to the structures labelled (a) to (e)?

    Human eye unlabelled
    Figure 5.3  Can you name these structures?
  • Figure 5.3: The labels you should have added are (a) eyelashes; (b) eyelid; (c) sclera; (d) pupil; (e) iris.

Next we turn to a major cause of blindness all over the world that results from problems in one of the structures you just learned about.

5.1.4  Lens and aqueous humour

5.2  Cataracts