Question

Least distance of distinct vision for a healthy human eye is

• A. \(15 \text{ cm}\)
• B. \(25 \text{ cm}\)
• C. \(30 \text{ cm}\)
• D. \(35 \text{ cm}\)

Hint:

The least distance of distinct vision of a normal human eye is \(25 \text{ cm}\). It is also called the near point.

Answer 1

The Correct Option is B

Concept:
The least distance of distinct vision is the minimum distance from the eye at which an object can be seen clearly without strain. For a normal healthy human eye, this distance is approximately: \[ 25 \text{ cm} \] This distance is also called the near point of the eye.

Step 1: Understanding the near point of the eye.
When an object is brought very close to the eye, the eye lens tries to adjust its focal length to focus the image on the retina. However, there is a limit to this adjustment. The nearest distance at which the eye can still focus clearly is called the least distance of distinct vision. \[ \boxed{25 \text{ cm}} \]

Step 2: Checking the given options.
Among the given values: \[ 15 \text{ cm},\ 25 \text{ cm},\ 30 \text{ cm},\ 35 \text{ cm} \] the scientifically accepted value for a normal eye is: \[ 25 \text{ cm} \] Therefore, the correct option is: \[ \boxed{(2)\ 25 \text{ cm}} \]