Purchase this article with an account.
Brian Vohnsen; The integrated Stiles-Crawford effect: understanding the role of pupil size and outer-segment length in foveal vision. Journal of Vision 2021;21(9):1806. doi: https://doi.org/10.1167/jov.21.9.1806.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The Stiles-Crawford effect of the first kind (SCE-I) describes a psychophysical change in perceived brightness related to the angle of incidence of a ray of light onto the retina. The effect is commonly explained as being due to angular-dependent waveguiding by foveal cones, yet the SCE-I is largely absent from similar-shaped rods suggesting that a different mechanism than waveguiding is at play. To examine this, we have devised a flickering pupil method that directly measures the integrated SCE-I for normal pupil sizes in normal vision rather than relying on mathematical integration of the standard SCE-I function as determined with Maxwellian light. Our results show that the measured effective visibility for normal foveal vision is related to visual pigment density in the three-dimensional retina rather than waveguiding. We confirm the experimental findings with a numerical absorption model using Beer-Lambert’s law for the visual pigments.
This PDF is available to Subscribers Only