Chromatic aberration of the vertebrate lens.
A split-laser technique employing red and blue lasers was used for direct measurement of longitudinal chromatic aberration of excised lenses from a spectrum of vertebrates (fish, amphibians, birds and mammals). The chromatic aberration (442-633 nm) of lenses of most species amounts to a relatively constant 4.6% of equivalent focal length. Dog lenses show somewhat larger amounts (5.7%) while duck and rock bass lenses show less wavelength variation in focal length (3.42-2.70%). In general, chromatic aberration varies little with lens eccentricity, although this point requires further study with more attention to paraxial measurements.