PS: Vision in a complete achromat: a personal account is a very interesting feature on achromatopsia by vision scientist Knut Nordby.    From Wordnik.com.  [Not-so-new colour recognition] Reference

The magician's tale / David Hunt —An achromat suffering from total color blindness, Kay possesses a vision that informs her world and sharpens her skills as talented photographer.    From Wordnik.com.  [3/16: New at the library this week] Reference

You can, for example, buy semi-plan apochromatic objectives and plan achromat objectives.    From Wordnik.com.  [MAKE Magazine] Reference

An achromat brings those two wavelengths to the same focus, with other wavelengths very slightly out of focus.    From Wordnik.com.  [MAKE Magazine] Reference

The first section on the knowledge argument has a number of special treats: Knut Nordby, the achromat color scientist, with a piece on what it's like to be in Mary's situation.    From Wordnik.com.  [fragments of consciousness] Reference

An apochromat is corrected for three specific wavelengths of light -- usually red, green, and blue -- and brings those three wavelengths to the same focus, providing slightly sharper images than an achromat.    From Wordnik.com.  [MAKE Magazine] Reference

TwoNeilHD DOF adaptor - vibrating gg, no achromat.    From Wordnik.com.  [Vimeo / Recent Public Videos] Reference