Combined effect of wavelength and polarization in double-pass retinal images in the human eye.

A polychromatic double-pass setup was developed to study the effects of wavelength and polarization on retinal image quality. The results show that the central part of the images was similar for all wavelengths (543, 633 and 780 nm) and polarization states. However, the image tails increased significantly when using infrared light for all the polarization states used. For the set of subjects involved in the study, ocular diattenuation presented individual differences, however significant changes were not found across the different wavelengths. Moreover the Stokes vectors providing the maximum intensity transmittance varied across subjects and corresponded to elliptically polarized light. These non-negligible diattenuation effects might affect the performance of clinical devices which only take into account ocular birefringence.