The influence of the Stiles-Crawford peak location on visual performance.
We investigated the influence of the Stiles-Crawford peak location on visual acuity, contrast sensitivity and phase transfer with 6 mm diameter pupils in two subjects. Apodising filters were used to move the peak. One subject (SM) had her natural peak 0.9 mm below pupil centre, and visual performance was measured for both this peak position and when the peak was moved to the same distance above pupil centre. The other subject (DAA) had a more centred peak and visual performance was measured for this peak position and when the peak was moved both 2.3 mm temporally and 2.6 mm nasally. Measurements of contrast sensitivity and phase transfer were compared with predictions based on aberration measurements. The peak position had definite influence on performance, but this was mainly noticeable when subjects were defocused e.g. SM's visual acuity was reduced by 0.13 log units under the peak-shifted condition at -2D (hypermetropic) defocus.
Atchison
David A
DA
Centre for Eye Research, School of Optometry, Queensland University of Technology, Victoria Park Road, Kelvin Grove, 4059, Qld, Australia. d.atchison@qut.edu.au
Marcos
Susana
S
Scott
Dion H
DH
D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology*; D006801:Humans; D006956:Hyperopia / Q000503:physiopathology / Q000523:psychology; D008875:Middle Aged; D011680:Pupil; D012160:Retina / Q000502:physiology; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology*