Abstract
Purpose: :
This study investigates the hypothesis that the off-axis vision of avian eyes is adapted to their environment. In the preliminary phase of this project, aberrations in human peripheral vision were evaluated for comparison with the findings in the animal study.Pigeons are highly visual and possess a very specialized retina with adaptations for peripheral viewing. As a result, they are a suitable animal model to work with in the field of vision science. The eyes of pigeons are laterally positioned, providing a panoramic view of the world. Most birds also have a secondary specialization of the temporal retina for frontal viewing
Methods: :
A Hartmann-Shack wavefront sensor (HSWFS) has been developed to measure the ocular aberrations of the eye. The birds were anesthetized during the measurements and the pupil was dilated to allow access to peripheral retinal locations. Twenty measurements were made at each position and each measurement was based on an average of ten frames.
Results: :
The present results (see Fig 1) indicate that the amount of aberrations increases with eccentricity from visual axis in the avian eye. For the frontal visual field (temporal retina) in the avian eye, the value of the Zernike coefficients corresponding to astigmatism are lower than on axis and in the posterior field (nasal retina).