{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,12]],"date-time":"2026-09-12T06:03:42Z","timestamp":1789193022288,"version":"build-2803163510"},"reference-count":30,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2025,5,17]],"date-time":"2025-05-17T00:00:00Z","timestamp":1747440000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"College of Applied Medical Sciences Research Centre"},{"name":"Deanship of Scientific Research at King Saud University"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Life"],"abstract":"<jats:p>Background: Measuring contrast sensitivity for each of the three cone types separately allows for a more precise and clinically valuable assessment of color vision. This study examined how pupil size affects cone contrast sensitivity (CCS). Methods: This study included 50 participants of equal gender. The mean age was 20.88 (\u00b11.8) years. Using the ColorDx, a Landolt C stimulus of various sizes in an adaptive screening mode, we sequentially determined contrast sensitivity for long-, medium-, and short-wavelength stimuli. Two consecutive measurements were performed on participants, one with their natural pupil size (range 4\u20135 mm diameter) and, subsequently, with six artificial eye pupils (1 mm to 6 mm). Results: Generally, the 1 mm pupil size caused the greatest reduction in contrast sensitivity for two of the three cones. There was no significant main effect of sex (F = 0.96, df = 1, p = 0.32) on the log cone contrast sensitivity of the L-cone. However, pupil size had a significant main effect (F = 116.1, df = 6, p &lt; 0.001). Within each sex, the log CCS was significantly reduced as the pupil size decreased compared with the normal pupil size. Conclusions: New technologies that assess individual cone pathway functions could potentially assist in identifying early or progressive conditions that may impact color vision pathways from the retina to the brain. Standardized protocols\u2014such as controlled retinal illumination\u2014are critical to avoid misinterpretation.<\/jats:p>","DOI":"10.3390\/life15050801","type":"journal-article","created":{"date-parts":[[2025,5,20]],"date-time":"2025-05-20T06:54:28Z","timestamp":1747724068000},"page":"801","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["The Effect of Pupil Size on Cone Contrast Sensitivity"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3225-3075","authenticated-orcid":false,"given":"Ali","family":"Almustanyir","sequence":"first","affiliation":[{"name":"Optometry Department, College of Applied Medical Sciences, King Saud University, Riyadh 11362, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1802-2403","authenticated-orcid":false,"given":"Meznah S.","family":"Almutairi","sequence":"additional","affiliation":[{"name":"Optometry Department, College of Applied Medical Sciences, King Saud University, Riyadh 11362, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0922-8541","authenticated-orcid":false,"given":"Amal","family":"Aldrwish","sequence":"additional","affiliation":[{"name":"Optometry Department, College of Applied Medical Sciences, King Saud University, Riyadh 11362, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4105-5513","authenticated-orcid":false,"given":"Nabeela","family":"Hasrod","sequence":"additional","affiliation":[{"name":"Department of Optometry, Faculty of Health Sciences, University of Johannesburg, Johannesburg 2025, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bader A.","family":"Alqhtani","sequence":"additional","affiliation":[{"name":"Optometry Department, College of Applied Medical Sciences, King Saud University, Riyadh 11362, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7286-3505","authenticated-orcid":false,"given":"Tahani","family":"Alqahtani","sequence":"additional","affiliation":[{"name":"Optometry Department, College of Applied Medical Sciences, King Saud University, Riyadh 11362, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2994-1472","authenticated-orcid":false,"given":"Muteb","family":"Alanazi","sequence":"additional","affiliation":[{"name":"Optometry Department, College of Applied Medical Sciences, King Saud University, Riyadh 11362, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9389-4722","authenticated-orcid":false,"given":"Mansour","family":"Alghamdi","sequence":"additional","affiliation":[{"name":"Optometry Department, College of Applied Medical Sciences, King Saud University, Riyadh 11362, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5465-5924","authenticated-orcid":false,"given":"Essam","family":"Almutleb","sequence":"additional","affiliation":[{"name":"Optometry Department, College of Applied Medical Sciences, King Saud University, Riyadh 11362, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Balsam","family":"Alabdulkader","sequence":"additional","affiliation":[{"name":"Optometry Department, College of Applied Medical Sciences, King Saud University, Riyadh 11362, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1185-8067","authenticated-orcid":false,"given":"Faisal","family":"Fakhouri","sequence":"additional","affiliation":[{"name":"Department of Biomedical Technology, College of Applied Medical Sciences, King Saud University, Riyadh 11362, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7986-1326","authenticated-orcid":false,"given":"Mosaad","family":"Alhassan","sequence":"additional","affiliation":[{"name":"Optometry Department, College of Applied Medical Sciences, King Saud University, Riyadh 11362, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,5,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"313","DOI":"10.1364\/JOSAA.29.000313","article-title":"Worldwide prevalence of red-green color deficiency","volume":"29","author":"Birch","year":"2012","journal-title":"J. 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