December 2022
Volume 22, Issue 14
Open Access
Vision Sciences Society Annual Meeting Abstract  |   December 2022
EasyEyes measures thresholds online
Author Affiliations & Notes
  • Denis Pelli
    New York University
  • Peiling Jiang
    New York University
  • Augustin Burchell
    New York University
  • Mai Nguyen
    New York University
  • Francesca Hardy
    New York University
  • Najib Majaj
    New York University
  • Footnotes
    Acknowledgements  National Eye Institute Grant 1R01EY027964 to Denis Pelli and Jon Winawer.
Journal of Vision December 2022, Vol.22, 4494. doi:
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    • Get Citation

      Denis Pelli, Peiling Jiang, Augustin Burchell, Mai Nguyen, Francesca Hardy, Najib Majaj; EasyEyes measures thresholds online. Journal of Vision 2022;22(14):4494.

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      © ARVO (1962-2015); The Authors (2016-present)

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The scientist uses any spreadsheet to write a table specifying parameter values for each condition of every block to measure spacing thresholds, to study crowding. The scientist submits her table to the one-page web app, which compiles the table and returns the URL of a new one-page web app that can be given to multiple participants to measure their thresholds. EasyEyes uses the "virtual chinrest" tricks of Li et al. (2020) and the webcam to measure screen size and track viewing distance and gaze. Accurate fixation just before stimulus presentation is encouraged by asking the participant to click the crosshair to initiate each trial. For each of four diverse fonts (P22 Aragon, Sloan, Monotype Times New Roman, and Google Roboto Mono), we measured spacing threshold twice in each of 20 observers. The test-retest SD of log threshold was 0.24±0.05 (mean±sd of sd). This is similar to our best in-person threshold measurement with an Eyelink eye tracker (Kurzawski, et al. 2021). Across fonts, the mean Bouma factor (ratio of spacing threshold to radial eccentricity) spans a nearly 2:1 range: 0.17 (Aragon), 0.21 (Sloan), 0.28 (Times New Roman), and 0.30 (Roboto Mono). EasyEyes is open source, built on PsychoPy/JS, and uses Prolific to recruit online participants.


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