Thus examined, the departure of the eye from achromatism appears very gross indeed.
The achromatism of prisms depends upon the same principles, and it is effected in the same way as that of lenses.
The reflecting telescope was invented; the recognized possibility of achromatism led to an improvement in the refractor.
As the diameter of the lens was so small in comparison with its focal length, its want of achromatism was inappreciable.
Leonhard Euler in 1747 had suggested that achromatism might be obtained by the combination of glass and water lenses.
It would seem that the eye is but little sensitive to colours thus presented, perhaps on account of its own want of achromatism.
It is upon this principle that the achromatism of the image is produced, the different colored rays being united into one focus.
achromatism a·chro·ma·tism (ā-krō'mə-tĭz'əm, ə-krō'-)
The quality of being achromatic.
The correction of chromatic aberration by combining lenses of different refractive indexes and different dispersion.