Question

The least distance of distinct vision for a normal human eye is approximately:

• A. 2.5 cm
• B. 25 cm
• C. 2.5 m
• D. 25 m

Answer 1

Answer:

B. 25 cm

Vision Physiology

• The least distance of distinct vision, also known as the near point of the eye, is the minimum distance at which an object can be placed so that it can be seen clearly without any strain on the eye muscles.

• For a normal human adult, this distance is standardly defined as 25 cm (approximately 10 inches).

• The ciliary muscles of the eye play a crucial role in this process by adjusting the focal length of the lens to focus on objects at varying distances, a phenomenon known as accommodation.