To solve the problem, we need to recall the standard value for the least distance of distinct vision in a normal human eye.
1. Definition:
The least distance of distinct vision is the minimum distance at which the human eye can see objects clearly without any strain. This is the closest point to the eye at which an object can be brought into sharp focus.
2. Standard Value:
For a normal human eye, the least distance of distinct vision is: $ 25 \, \text{cm} $
Final Answer:
The least distance of distinct vision is $25 \, \text{cm}$
Tara's grandmother is 70 years old and has a passion for embroidery. She faces difficulty in threading the needle as the eye of the needle appears blurred. The ophthalmologist diagnosed it as an age-related disorder. 
(a) Name the eye disorder she is suffering from.
(b) How can the above defect be corrected?
(c) Where is the image formed in the above disorder?