Question

What is the difference between least distance of distinct vision and near point?

Answer 1

In optometry, the least distance of distinct vision (LDDV) or the reference seeing distance (RSD) is the closest someone with "normal" vision (20/20 vision) can comfortably look at something. In other words LDDV is the minimum comfortable distance between the naked human eye and a visible object. The LDDV is widely accepted as being 250mm (10 inches).

In optics, the closest point at which an object can be brought into focus by the eye is called the eye's near point. A standard near point distance of 25 cm is typically assumed in the design of optical instruments, and in characterizing optical devices such as magnifying glasses.

Both distances are the same and are basicly the same thing. The only difference in that near point is the term used when talking about corrective lenses while the other term is used more generally in optometry. If this isn't specific enough, try re-posting this question in the medical section rather than geography