ISSN : 1229-6457(Print)
ISSN : 2466-040X(Online)
ISSN : 2466-040X(Online)
The Korean Journal of Vision Science Vol.27 No.3 pp.201-209
DOI : https://doi.org/10.17337/JMBI.2025.27.3.201
DOI : https://doi.org/10.17337/JMBI.2025.27.3.201
Effect of Binocular Visual Function Pupil Diameter on Contrast Sensitivity
Abstract
Purpose : This study aimed to investigate the effects of pupil diameter and binocular visual function on binocular contrast sensitivity.
Methods : A total of 38 healthy adults with no systemic or ocular diseases participated in this study. After refractive error correction, phoria, accommodation, accommodative lag, and accommodative facility were measured. Binocular contrast sensitivity, both static and dynamic, was measured using the MonCV3 device (Metrovision, France) at spatial frequencies of 0.8, 1.6, 3.2, 6.4, 12.8, and 25.6 cycles per degree (cpd). Pupil diameter was measured under various illumination levels (100, 10, 1, and 0 cd/m2).
Results : Distance phoria showed a significant correlation with dynamic contrast sensitivity at 6.4 cpd (r = 0.373, p = 0.043), indicating that an increase in exophoria may lead to decreased dynamic contrast sensitivity. Accommodative function did not show a significant correlation with either static or dynamic binocular contrast sensitivity. While pupil diameter under individual illumination conditions did not correlate significantly with contrast sensitivity, the difference between maximum and minimum pupil diameters showed a significant negative correlation with both static and dynamic contrast sensitivity at 1.6 cpd (r = -0.393, p = 0.016; r = -0.367, p = 0.046, respectively). This suggests that large fluctuations in pupil size may reduce contrast sensitivity at low spatial frequencies.
Conclusion : Even with refractive error correction, individuals with large distance phoria or large pupil diameter variation between photopic and scotopic conditions may experience reduced visual quality and decreased clarity at night. In clinical practice, when patients report low satisfaction with vision despite a corrected visual acuity 1.0, contrast sensitivity testing should be considered.
Methods : A total of 38 healthy adults with no systemic or ocular diseases participated in this study. After refractive error correction, phoria, accommodation, accommodative lag, and accommodative facility were measured. Binocular contrast sensitivity, both static and dynamic, was measured using the MonCV3 device (Metrovision, France) at spatial frequencies of 0.8, 1.6, 3.2, 6.4, 12.8, and 25.6 cycles per degree (cpd). Pupil diameter was measured under various illumination levels (100, 10, 1, and 0 cd/m2).
Results : Distance phoria showed a significant correlation with dynamic contrast sensitivity at 6.4 cpd (r = 0.373, p = 0.043), indicating that an increase in exophoria may lead to decreased dynamic contrast sensitivity. Accommodative function did not show a significant correlation with either static or dynamic binocular contrast sensitivity. While pupil diameter under individual illumination conditions did not correlate significantly with contrast sensitivity, the difference between maximum and minimum pupil diameters showed a significant negative correlation with both static and dynamic contrast sensitivity at 1.6 cpd (r = -0.393, p = 0.016; r = -0.367, p = 0.046, respectively). This suggests that large fluctuations in pupil size may reduce contrast sensitivity at low spatial frequencies.
Conclusion : Even with refractive error correction, individuals with large distance phoria or large pupil diameter variation between photopic and scotopic conditions may experience reduced visual quality and decreased clarity at night. In clinical practice, when patients report low satisfaction with vision despite a corrected visual acuity 1.0, contrast sensitivity testing should be considered.