Least distance of distinct vision

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:^[2]

{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.
^ Pedrotti, Frank L.; Pedrotti, Leno S. (1996). Introduction to optics. Prentice-Hall international editions (2. ed., [Nachdr.] ed.). Englewood Cliffs, NJ: Prentice-Hall International. p. 131. ISBN 978-0-13-016973-0.

[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.

[2] Pedrotti, Frank L.; Pedrotti, Leno S. (1996). Introduction to optics. Prentice-Hall international editions (2. ed., [Nachdr.] ed.). Englewood Cliffs, NJ: Prentice-Hall International. p. 131. ISBN 978-0-13-016973-0.

[1]

[2]

See also

References