Influence of Stiles-Crawford effect apodization on spatial visual performance with decentered pupils

Area of Science:

• Ophthalmology
• Visual Optics
• Optical Engineering

Background:

• The Stiles-Crawford effect (SCE) describes how the sensitivity of retinal photoreceptors varies with the angle of light entry into the pupil.
• Pupil decentration can induce optical aberrations, affecting image quality and subjective visual measurements.

Purpose of the Study:

• To theoretically predict the influence of the Stiles-Crawford effect (SCE) on the eye's optical performance.
• To assess the SCE's impact on subjective measurements of transverse aberrations with decentered pupils.

Main Methods:

• Modeled the SCE as a pupil apodization function.
• Utilized theoretical estimates of the optical-transfer function (OTF) and line-spread function (LSF) as image-quality criteria.
• Calculated the effect of pupil decentration on transverse chromatic aberrations (TCA).

Main Results:

• The SCE provides a small improvement in image quality by compensating for aberrations caused by pupil decentration.
• Using the LSF centroid as an image placement criterion, the average SCE reduced the influence of pupil decentration on subjective TCA by 30% for 5-mm pupils.
• Decentering the SCE caused a shift in subjective TCA of 1.4 arc min/mm for 5-mm pupils at specific wavelengths.

Conclusions:

• The SCE offers a minor compensatory effect against aberrations from pupil decentration.
• The theoretical reduction in TCA influence by SCE is less than previously reported in experimental studies, warranting further investigation.
• The SCE's position within the pupil significantly impacts subjective TCA measurements.