Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Impact of Blur and Disparity Cues on Accommodation, Vergence, and Pupil Size in Response to Static Stimuli in Adolescents With and Without Concussion.

Investigative ophthalmology & visual science·2026
Same author

Impact of Stimulus Size and Cognitive Demand on Accommodation and Pupil Size in Children and Adults.

Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists)·2026
Same author

Web-Based Amblyopia Decision Support Tool.

JAMA ophthalmology·2026
Same author

At-home visual acuity in children using a custom iPhone application compared with standardized in-office visual acuity testing.

Optometry and vision science : official publication of the American Academy of Optometry·2026
Same author

Evaluating post-concussion symptom profiles using the convergence insufficiency symptom survey in a pediatric and adolescent cohort.

Frontiers in neuroscience·2026
Same author

Test-retest reliability of clinical accommodative measures in adolescents.

Optometry and vision science : official publication of the American Academy of Optometry·2026

Related Experiment Video

Updated: Apr 19, 2026

Assessing Pupil-linked Changes in Locus Coeruleus-mediated Arousal Elicited by Trigeminal Stimulation
07:26

Assessing Pupil-linked Changes in Locus Coeruleus-mediated Arousal Elicited by Trigeminal Stimulation

Published on: November 26, 2019

8.8K

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

Jennifer X Haensel1, Kristin E Slinger2, Tyler J Vandiver2

  • 1Spencer Center for Vision Research, Byers Eye Institute at Stanford University, Palo Alto, California, USA. jhaensel@stanford.edu.

Ophthalmic & Physiological Optics : the Journal of the British College of Ophthalmic Opticians (Optometrists)
|April 17, 2026
PubMed
Summary

The PowerRef 3 photorefractor accurately measures gaze position within ±8° horizontally and -4° to +10° vertically. Beyond these limits, gaze and refractive measurements may be impacted.

Keywords:
Eye-trackingGazePhotorefractionVergence

More Related Videos

Quantification of Oculomotor Responses and Accommodation Through Instrumentation and Analysis Toolboxes
08:27

Quantification of Oculomotor Responses and Accommodation Through Instrumentation and Analysis Toolboxes

Published on: March 3, 2023

1.6K
A Method to Quantify Visual Information Processing in Children Using Eye Tracking
09:47

A Method to Quantify Visual Information Processing in Children Using Eye Tracking

Published on: July 9, 2016

18.4K

Related Experiment Videos

Last Updated: Apr 19, 2026

Assessing Pupil-linked Changes in Locus Coeruleus-mediated Arousal Elicited by Trigeminal Stimulation
07:26

Assessing Pupil-linked Changes in Locus Coeruleus-mediated Arousal Elicited by Trigeminal Stimulation

Published on: November 26, 2019

8.8K
Quantification of Oculomotor Responses and Accommodation Through Instrumentation and Analysis Toolboxes
08:27

Quantification of Oculomotor Responses and Accommodation Through Instrumentation and Analysis Toolboxes

Published on: March 3, 2023

1.6K
A Method to Quantify Visual Information Processing in Children Using Eye Tracking
09:47

A Method to Quantify Visual Information Processing in Children Using Eye Tracking

Published on: July 9, 2016

18.4K

Area of Science:

  • Ophthalmology
  • Optometry
  • Vision Science

Background:

  • Accurate gaze position measurement is crucial for reliable refractive error assessment.
  • Photorefractors are widely used for non-invasive refractive measurements.
  • Understanding the performance limits of photorefractors is essential for clinical application.

Purpose of the Study:

  • To evaluate the gaze position measurement quality of the PowerRef 3 photorefractor.
  • To assess how gaze position affects refractive measurements obtained with the PowerRef 3.

Main Methods:

  • Gaze position was recorded using the PowerRef 3 (50 Hz) in 20 adults at 39 fixation locations.
  • Spatial accuracy, precision (RMS-mean, RMS-S2S), and data loss were assessed.
  • EyeLink 1000 (500 Hz) was used for reference gaze metrics.

Main Results:

  • PowerRef 3 showed spatial accuracy of 1.45° (h) and 1.29° (v) with variable precision.
  • Data loss occurred primarily at eccentric horizontal (±20°-±24°) and downward gaze positions.
  • Refractive measurements showed hyperopic shifts beyond +10° horizontally and downward, and myopic shifts leftward.

Conclusions:

  • The PowerRef 3 reliably records gaze within ±8° horizontally and -4° to +10° vertically.
  • Gaze positions outside these ranges may impact both gaze tracking and refractive measurements.
  • Clinical use should consider these limitations for optimal accuracy.