Original Article February 25, 2026 February 25, 2026

Tumbling-hand optotype: a novel gesture-based tool for visual acuity assessment in neurodivergent populations

DOI: 10.37039/1982.8551.20260011

ABSTRACT

Objective:

This study aimed to validate the psychometric properties, feasibility, and clinical utility of the Tumbling-Hand test.

Methods:

The validation process involved two phases. In neurotypical participants, VA thresholds of the Tumbling-Hand test were compared with the printed Tumbling E test, with repeatability assessed using intraclass correlation coefficients (ICCs) and Bland-Altman analysis. In neurodivergent participants, the feasibility and success rates of the Tumbling-Hand test were evaluated against the Tumbling E and Landolt C tests. Statistical analyses, including McNamar’s and chi-square tests, were performed to assess performance differences across age, gender, and disability type.

Results:

In neurotypical participants (n = 75), the Tumbling-Hand test demonstrated excellent reproducibility, with ICCs exceeding 0.90 and agreement comparable to the Tumbling E test. Among neurodivergent participants (n = 80), the Tumbling Hand test achieved the highest success rates, particularly as a secondary test (72.73%, p = 0.001). Success rates were significantly higher in individuals aged ≥10 years (p < 0.01), with no significant differences by gender. The Tumbling Hand test demonstrated the highest combined success rate in Autism Spectrum Disorder (72.22%).

Conclusion:

The Tumbling-Hand test is a reliable, reproducible, and inclusive tool for VA assessment. Its adaptability makes it particularly valuable for neurodivergent populations, warranting further validation in broader clinical contexts.