Abstract
PURPOSE: The optics of the eye affect the retinal image, and do so unequally at each wavelength. This causes the effective image sampled by each type of cone (S, M, and L) to be different because each cone-type has its own spectral selectivity. Here, we use a recent model of the eye's optics to determine (1) the point spread function at each wavelength, (2) the modulation transfer function for each type of cone for broadband (EEW) light, and (3) the variation in image quality for each cone type in the population of observers. METHOD: The “Indiana Eye” (Thibos, Bradley & Hong, 2002) characterizes the eye's optics, including longitudinal chromatic aberration and higher order wave aberrations. Wave aberrations are modeled using Zernike polynomials, which in the population are characterized by a multivariate Gaussian. RESULTS & CONCLUSIONS: Imperfections in the eye's optics are claimed to make comparable the image quality for all three types of cone (McLellan et al, Nature, 2002). Our results find this theoretically possible for extreme observers but not at all typical. A standard ‘median’ observer has far worse contrast sensitivity for S than L and M cones. The technique can be generalized to determine the retinal distribution of light from any 2D spectral image for a population of observers.
Supported by NIH grant EY-04802