Definitions for "Micro lens"
A lens for close-up photography; designed to focus continuously from infinity down to a reproduction ratio of 1: 2, or with a matched extension ring or teleconverter down to 1: 1; available in normal or telephoto focal lengths to provide a variety of free working distances; with the exception of Nikon, this type of lens is called a "Micro Nikkor" lens. Also see above, Macro or Makro (Usually for German origin lenses)..
Lens for microscopic photography. Not to be confused with a Macro lens. (See Macro lens, Macro photography).
The Micro-Nikkor is the Nikon Corporation's name for their close-up 'Macro' lens. (see Macro lens)