Summary of Study Session 5

In this study session, you have learned that:

  1. The eye serves an important purpose of vision and its function is comparable to the function of a camera in taking a photo.
  2. The main structures of the eyeball are the sclera, cornea, pupil, iris and lens, all of which have the important function of transmitting light onto the retina at the back of the eye where the image is formed.
  3. Cataracts and eye injuries are important causes of blindness worldwide, where cataract alone contributes to 48% of all people who are totally blind.
  4. The early symptoms of cataract are blurred vision, difficulty seeing in bright light and poor colour vision.
  5. Cataract progression can be slowed by preventing eye injury, strict control of blood sugar, and avoiding exposure to smoke from cigarettes and indoor fires. Lack of vitamin A in the diet and measles infection are other causes of blindness.
  6. Common causes of eye injury are scratches, chemical splashes, penetrating and blunt injuries, and cuts to the eyelids.
  7. Damage to the cornea by the eyelashes turning inwards and scratching it is an important cause of blindness. It is due to a chronic eye infection called trachoma.
  8. Children often insert small foreign objects into their ears, which can lead to problems of ear infection and deafness. Some of the common objects they play with are beans, peas, beads and fruit seeds.
  9. Careful removal of foreign objects from the ears prevents ear infection, which is an important cause of deafness, especially in children.

5.5  Ear injuries due to foreign objects

Self-Assessment Questions (SAQs) for Study Session 5