Evidence map›Paper›PMID 41998475›Full record

ArticleOphthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists)2026

A Quantitative Evaluation of the PowerRef 3 for Measuring Gaze Position.

Jennifer X Haensel, Kristin E Slinger, Tyler J Vandiver, Georgia Hutchinson, Amber Hu, Christabel A Ameyaw Baah, Tawna L Roberts

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Article in Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists), 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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5 · Who and what money

Authors and funding

7 authors.

Jennifer X HaenselSpencer Center for Vision Research, Byers Eye Institute at Stanford University, Palo Alto, California, USA. jhaensel@stanford.edu.
Kristin E SlingerSpencer Center for Vision Research, Byers Eye Institute at Stanford University, Palo Alto, California, USA.
Tyler J VandiverSpencer Center for Vision Research, Byers Eye Institute at Stanford University, Palo Alto, California, USA.
Georgia HutchinsonSpencer Center for Vision Research, Byers Eye Institute at Stanford University, Palo Alto, California, USA.
Amber HuSpencer Center for Vision Research, Byers Eye Institute at Stanford University, Palo Alto, California, USA.
Christabel A Ameyaw BaahSpencer Center for Vision Research, Byers Eye Institute at Stanford University, Palo Alto, California, USA.
Tawna L RobertsSpencer Center for Vision Research, Byers Eye Institute at Stanford University, Palo Alto, California, USA.

Funding

Afferent and Efferent Visual Systems During Abnormal Vision DevelopmentR01EY029307 · NEI · STANFORD UNIVERSITY · PI ROBERTS, TAWNA · 2020 to 2024
$3.0M
NEI NIH HHS R01 EY029307NIH/NEI R01-EY029307Research to Prevent Blindness Walt and Lilly Disney Award for Amblyopia ResearchU.S. Department of Defense W81XWH-21-1-0961
6 · The paper itself

Abstract

purposeTo evaluate the quality of gaze position measurements from the PowerRef 3 photorefractor and assess the impact of gaze position on the PowerRef 3 refractive measurements.

methodsMonocular right-eye gaze was recorded in 20 adults (16 female, 4 male; 25.0±7.4 years) using the PowerRef 3 photorefractor (50 Hz). Participants fixated a target at 120 cm in 39 randomised locations (±24° horizontally [h], ±14° vertically [v]; 2° steps from centre). At each location, spatial accuracy, precision (root mean square of distances between samples and mean fixation [RMS-mean] and between successive samples [RMS-S2S]) and data loss were assessed. The impact of gaze position on refractive measurements was also examined. Gaze position data were also recorded using the EyeLink 1000 (500 Hz) to provide reference quality metrics.

resultsThe PowerRef 3 had spatial accuracy of h = 1.45° ± 0.41° and v = 1.29° ± 0.15° and variable precision (RMS-Mean: h = 1.37° ± 0.12°, v = 1.32° ± 0.11°; RMS-S2S: h = 1.96° ± 0.16°, v = 1.90° ± 0.18°). Reference metrics obtained using the EyeLink showed slightly higher accuracy and precision (accuracy: h = 0.53° ± 0.09°, v = 0.52° ± 0.09°; RMS-Mean: h = 0.17° ± 0.02°, v = 0.19° ± 0.03°; RMS-S2S: h = 0.08° ± 0.01°, v = 0.07° ± 0.01°). Notable data loss for the PowerRef 3 was primarily observed at eccentric horizontal locations (0°-±16°: ≤30% of participants; ±20°-±24°: 35-70%; EyeLink 0°-±24°: ≤5%). PowerRef 3 data loss was also greater for lower vertical targets (≥30%) than for higher ones (≤20%). Relative to the pupillary axis, refractive measurements were more hyperopic beyond +10° horizontally (rightward gaze; 0.36-0.62 D) and beyond -6° vertically (downward; 0.59-1.44 D) and more myopic (≤1.29 D) between -10° to -18° horizontally (leftward).

conclusionThe PowerRef 3 can record gaze positions within ±8° horizontally and -4° (downward) to +10° (upward) vertically without a significant impact on both gaze and refractive measurements.

Indexed as

Eye MovementsFixation, OcularRefraction, OcularRefractive ErrorsAdultFemaleHumansMaleReproducibility of ResultsYoung AdultEye-trackingGazePhotorefractionVergence

Identifiers

PMID41998475
PMCPMC13368894

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.