How do you find least distance of distinct vision?

  1. Hold the text book at certain distance with our hands.
  2. Try to read the content on the page.
  3. Gradually move the books towards eye, till it reaches very close to your eyes.
  4. You may see that printed letters on the page appear blurred or you will feel strain to read.
  5. Now move the book backwards to a position where you can see clear printed
    letters without strain.
  6. Ask your friend to measure distance between your eye and text book at this position.
  7. Note down its value.
  8. Repeat this activity with other friends and note down the distances for distinct
    vision in each case.
  9. Find the average of all these distances of clear vision.
  10. We notice that to see an object comfortably and distinctly, at a distance about 25 cm from your eyes.
  11. This 25 cm distance is called least distance of distinct vision.
  12. This value varies from person to person and with age.