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Updated: Jul 1, 2025

Subjective Refraction Test Using a Smartphone for Vision Screening
Published on: October 18, 2024
Manhattan Vision Screening and Follow-up Study (NYC-SIGHT): Vision and refractive error results
Daniel F Diamond1,2, Yocheved S Kresch2,3, Prakash Gorroochurn4
1Department of Ophthalmology, Columbia University, New York, NY, USA.
Clinical Relevance:
Optometrists can play a key role in providing access to eye care in underserved populations by organising community-based eye health screenings that include optometric exams to detect vision impairment and uncorrected refractive error.
Background:
Community-based eye health screenings and optometric exams were conducted in the NYC-SIGHT Study.
Methods:
A sub-analysis of vision impairment and refractive error results within a 5-year prospective, cluster-randomised clinical trial. Eligible individuals (age ≥40 years) were recruited from 10 affordable housing developments in Upper Manhattan. Developments were randomised into usual care (received glasses prescription only) and intervention (free glasses) groups. Participants with 6/12 visual acuity or worse, intraocular pressure 23-29 mmHg, or an unreadable fundus image were scheduled with the study optometrist for refraction and a non-dilated exam. Visual improvement data were obtained by comparing the presenting acuity at screening compared to the best corrected acuity after refraction by the optometrist. Chi-square, two-sample t-tests, and a stepwise multivariate logistic regression model were used to determined factors associated with improvable visual impairment.
Results:
Seven hundred and eight participants completed screening, 308 received an optometric exam. Those with improvable vision impairment (n = 251), mean age: 69.8 years, 70.5% female, 53% African American, 39.8% Hispanic, >95% had health insurance. Refractive error diagnosed in 87.8% of the participants; lines of improvement: 2 lines (n = 59), 3 to 5 lines (n = 120), and ≥6 lines (n = 72). Stepwise multivariate logistic regression analysis showed that participants with visual acuity 6/12 or worse (odds ratio 16.041, 95% confidence interval 6.009 to 42.822, p = 0.000) or a normal fundus image (odds ratio 2.783, 95% confidence interval 1.001 to 7.740, p = 0.05) had significantly higher odds of improvable vision impairment.
Conclusion:
This innovative, targeted community-based study included an optometrist who detected high rates of refractive error and improvable vision impairment in an underserved population living in New York City.

