Optical limitations of the Maxwellian view interferometer

Le Grand's technique for producing interference fringes directly on the retina was analyzed to determine the effect of ocular chromatic aberration on fringe parameters. For monochromatic light, fringe period is largely independent of refractive index of the ocular medium and of the axial location of the interferometer relative to the eye. Lateral displacement of the interferometer, however, shifts the retinal fringes by an amount which depends on wavelength. To close approximation, the relative shift between fringes of different colors is directly proportional to the amount of lateral displacement of the instrument, with the constant of proportionality equal to the longitudinal chromatic aberration of the eye. The net effect is a significant loss of retinal contrast for polychromatic fringes.