Question

The least distance of distinct vision is _____
$
  A.{\text{ 25m}} \\
  {\text{B}}{\text{.}}\,{\text{340cm}} \\
  {\text{C}}{\text{. 25cm}} \\
  {\text{D}}{\text{.17cm}} \\
 $

Answer 1

Hint: We here would follow the definition and properties of the least distinct vision of a normal human eye.

Complete step by step answer:
The normal human eye can focus a sharp image of an object on the eye for the conditions that objects are located anywhere from infinity to the certain point called the Near point. Whereas, the far point of the human eye with the normal vision is at the infinity.
The range of the vision of the human eye is the maximum distance up to the infinity unless no obstacle is placed in between such as wall, tree or any other object.
The least distance of the distinct vision is the minimum distance from the eye at which an object appears to be distinct and a very clear image is formed.
If the object is held closer to the eye than at this distance the image formed will be blurred and fuzzy. The location of the near point, or the least distance of distinct vision always changes with the age.
The least distance of distinct vision for a young adult by the way of normal vision is about 25 cm.
The least distance is denoted by - “d” The least distance of distinct vision (LDDV) is also known as the reference seeing distance (RSD).

So, the correct answer is “Option C”.

Note:
Always remember and go through the different terminologies such as visual angle, object angle, image angle, the angular magnification and the linear magnification. The least distance up to which we can see the objects clearly without any strain is called least distance of distinct vision.