Least_distance_of_distinct_vision References

The focal point F and focal length f of a positive (convex) lens, a negative (concave) lens, a concave mirror, and a convex mirror.

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.^[1] In other words, LDDV is the minimum comfortable distance between the naked human eye and a visible object.

The magnifying power (M) of a lens with focal length (f in millimeters) when viewed by the naked human eye can be calculated as:

{M}={\frac {250}{f}}.

References

^ Katz, Milton (August 1996). "Convergence Demands by Spectacle Magnifiers". Optometry and Vision Science. 73 (8): 540–545. doi: 10.1097/00006324-199608000-00004. ISSN 1538-9235. PMID 8869985. S2CID 21041392.

This optics-related article is a stub. You can help Wikipedia by expanding it.

[1] Katz, Milton (August 1996). "Convergence Demands by Spectacle Magnifiers". Optometry and Vision Science. 73 (8): 540–545. doi: 10.1097/00006324-199608000-00004. ISSN 1538-9235. PMID 8869985. S2CID 21041392.

[1]

See also

References