The closest distance for distinct, clear vision is called the near point. The general accepted distance is 10 inches (25 cm), but it is less for very young children and people with myopia (farsighted).
Discover For Yourself
Find the closest point where your eyes can form a clear image of an object viewed.
1. Hold an open book as close as possible to your face without touching your face.
2. Slowly move the book away from your face. Stop when you can read the print on the page. Then, move the book toward and away from your face until you find the closest distance the print can be from your eyes and have the sharpest, clear print.
(Note: If you wear reading glasses, repeat the experiment twice, first with your glasses and then without your glasses.)
3. Ask a helper to measure the distance the book is from your eyes. While the diagram shows a ruler being used, I suggest that you use a flexible measuring tape, such as the one shown.
This experiment is from Janice VanCleave’s Biology for Every Kid