Purpose To assess the repeatability of a prototype super acuity test chart for measuring visual acuity at 12.5 cm, and its ability to detect hyperopia in adolescents and young adults.

Methods Repeatability was estimated as within-subject standard deviation of three repeated super acuity measurements performed in 41 university students (19–26 years). Associations between super acuity and cycloplegic refractive errors, ocular biometry, distance visual acuity, accommodation, age, and sex were assessed in 119 high school students (16–18 years) using linear mixed-effects models. ROC curves and Youden index were used to estimate the best super acuity thresholds to detect rest hyperopia.

Results Mean super acuities in the university and high school cohorts were 0.14 ± 0.13 and 0.12 ± 0.11 logMAR, respectively. Repeatability was 0.031. Super acuity was poorer in those with uncorrected hyperopia [spherical equivalent refractive error (SER) ≥ 1.00 D] than the others [SER < 1.00 D; P = 0.039]. There were significant associations between poorer super acuity and more positive ametropia (SER; P = 0.026), poorer accommodation amplitude (P < 0.001), shorter axial length (P = 0.013), male sex (P < 0.001), and age (P = 0.037). Sensitivity and specificity for detecting hyperopia (SER ≥ 1.00 D) were 63.2% and 64.2%, respectively, at a super acuity threshold of 0.09 logMAR.

Discussion The super acuity prototype shows promise as a screening indicator for hyperopia. Further studies are needed to optimize the test and testing protocol, and to assess its ability to detect uncorrected hyperopia in children.

The authors have declared no competing interest.

The study was funded by the European Union Horizon Europe research and innovation program under grant agreement No 101070155 (The Equitable, Inclusive, and Human-Centered XR Project [XR4Human]) and the University of South-Eastern Norway.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The study was approved by the Regional Committee for Medical and Health Research Ethics in South East Norway and followed the Declaration of Helsinki. Written consent was obtained after the participants had received oral and written information about the study, and prior to any measurements.

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Yes

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Funding information: The study was funded by the European Union’s Horizon Europe research and innovation program under grant agreement No 101070155 (The Equitable, Inclusive, and Human-Centered XR Project [XR4Human]) and the University of South-Eastern Norway.

Commercial relationships disclosures: L. A. Hagen (None); E. Svarverud (None); I. Krastina (None); G. E. MacKenzie (None); R. C. Baraas (None)

All data produced in the present study are available upon reasonable request to the authors