Related Experiment Video
Updated: Jun 18, 2025
Subjective Refraction Test Using a Smartphone for Vision Screening
Published on: October 18, 2024
The Street Medicine Auto-refraction Technology Study: A Model for Screening and Treating Refractive Error in Persons
Anindya Samanta1, James Miller2, Max Jacobs3
1From the Department of Ophthalmology and Visual Sciences, Texas Tech University Health Sciences Center, Lubbock, Texas (A.S.).
Purpose:
The Street Medicine Auto-Refraction Technology study is an efficient and cost-effective treatment of refractive error (RE) and identification of potential non-RE pathology in people experiencing homelessness (PEHs).
Design:
Outreach evaluation for diagnosis and treatment.
Methods:
The internal medicine physicians/staff team used a protocol designed by ophthalmology to screen and treat PEHs. First, the uncorrected visual acuity (ucVA) was measured, which was defined as a patient's visual acuity without the use of any glasses. Those with 2-line improvement on pinhole testing (phVA) underwent handheld portable autorefraction (AR). During a second encounter, glasses purchased from the AR measurements were distributed, and vision was remeasured with the new glasses or current corrected visual acuity (ccVA). Patients with a final VA ≥0.3 logMAR (equivalent to Early Treatment Diabetic Retinopathy Study 20/40) were referred to an ophthalmology clinic for further evaluation.
Results:
This was a prospective study of 117 patients (226 eyes). ucVA was 0.64 logMAR (equivalent to Early Treatment Diabetic Retinopathy Study 20/87) for both the OD and the OS. A total of 90 of 98 (91.8%) patients successfully underwent AR; 80 of 88 (90.1%) patients received their glasses. For the 61 patients who completed their second visit, the average improvement in VA (ccVA - ucVA) was 5 lines. Twenty-three of 117 (19.7%) were referred to ophthalmology for further evaluation. Poststudy Likert surveys (1 = strongly disagree to 5 = strongly agree) showed patient satisfaction with the testing (4.7), the AR (4.6), seeing better (4.8), and doing activities with glasses (4.7). In addition, most patients agreed that they would not have obtained glasses without the study (4.7).
Conclusions:
This is a new model to screen RE and provide affordable glasses to PEHs in a nonambulatory setting. Patients with potential non-RE can be sent for further evaluation.
