Question

We cannot see an object clearly if it is placed very close to the eyes . why?

Answer 1

1. The minimum distance at which an object is placed from the normal eye so that it can be seen clearly without giving any strain on the eye is called as the distance of the distinct vision.

2. This distance is 25 cm for a normal human eye.

3. If the object is placed at a distance less than 25 cm , ciliary muscles is unable to adjust the lens there is a strain on the eye and it cannot be seen clearly.

4. Hence, an object should be placed at 25 cm or more to have a clear and sharp image on it on the retina.

Thanks!!

Answer 2

Explanation:

A normal eye is unable to clearly see the objects placed closer than 25 cm because the ciliary muscles of eyes are unable to contract beyond a certain limit.