My book defines:
The closest distance for which the lens can focus light on the retina is called the least distance of distinct vision or the near point. The standard value (for normal vision) taken here is $25\, \text{cm}$ (the near point is given the symbol $D$.)
However, in normal everyday life, I've always observed that I can still see objects clearly and distinctly for distances even at around $10\,\text{cm}$, which is much less than the value $D=25\, \text{cm}$. Yes, it does strain my eye to be looking at objects so close at $10 \,\text{cm}$ but I still can see them anyway, distinctly and clearly.
The Wikipedia article on LDDV is a stub. I couldn't any other useful information elsewhere.
Can anyone please resolve this dispute I've arrived at. Thanks!
Best Answer
The least distance of distinct vision is the minimum distance your eye lens can focus on an object without any strain. This means the eye is in a relaxed state. But eye is a self adjusting lens. When you try to see an object closer than 25 cm(for a normal eye), your eye automatically adjusts the focal length thus decreasing it. This is why your eye gets strained.