Activity Sheet 3: Focus on Seeing

To see objects that are close up the eye's lens must change shape according to the distance involved. The drawings show how lenses that are functioning correctly change shape to give a clear image. Look over the illustrations carefully and then fill in the statements to make them correct.

1. The shape of the lens is changed by_______________________________________.

2. For the image to be in focus, it must fall on the______________________________.

3. After passing through the lens, the position of the image is_____________________.

4. For nearsighted people, the eyeball may be too long and the image will fall in________ of the____________.

5. For farsighted people, the eyeball may be too short and the image will fall in_________ of the____________.

6. You might be_________________________if objects in the distance appear blurred.

7. Since focusing of an image in the eye is caused by the bending of light rays, your doctor of optometry can correct nearsightedness and farsightedness with glass or plastic_____________________________.


ANSWERS:

  1. ciliary muscles
  2. retina
  3. inverted or upside down
  4. front, retina
  5. back, retina
  6. nearsighted or myopic
  7. lenses