Question

why is normal eye not able to see clearly the object placed closer than 25cm

Answer 1

Because it's wavelength is placed under 25cm of distance.

Answer 2

Answer:

• the eye lens is composed of a fibrous, Jelly like material.
• to see closer and distance object, its focal length can be changed to certain extent by contraction and relaxation of ciliary muscles.
• the ability of the islands to adjust its focal length by contracting and relaxing it similarly muscles is called accommodation.
• to see closer object,cilinary muscles ,must decrease the focal length of eye lens.
• however, the focal length of a lens cannot be decrease below a certain minimum limit.
• to see an object comfortable and decently, the distance of object should be at least 25 cm from the eye.
• due to this ,a normal eye is not able to see clearly the object placed closer than 25 CM.