(Opt.) Free from color; transmitting light without decomposing it into its primary colors.
2.
(Biol.) Uncolored; not absorbing color from a fluid; said of tissue.
Achromatic lens (Opt.), a lens composed usually of two separate lenses, a convex and concave, of substances having different refractive and dispersive powers, as crown and flint glass, with the curvatures so adjusted that the chromatic aberration produced by the one is corrected by other, and light emerges from the compound lens undecomposed.
Achromatic telescope, or Achromatic microscope, one in which the chromatic aberration is corrected, usually by means of a compound or achromatic object glass, and which gives images free from extraneous color.
... different qualities. To these achromatic object glasses, as they are called, the great development of astronomical knowledge, since Newton's time, is due. But it must be remarked that, although the theoretical possibility of constructing an achromatic lens was investigated by Newton, he certainly came to the conclusion that the difficulty could not be removed by employing a composite objective, with two different kinds of glass. In this his marvellous sagacity in the interpretation of nature seems for once to have deserted him. We can, however, ... — Great Astronomers • R. S. Ball
...
