The Vision for Baltimore RCT, evaluating a citywide program of free vision screening and eyeglasses in elementary and middle school, recently published results. Quick take: High-quality RCT finds no impact on English language arts (ELA) or math scores on the state test over 2 years.

Study Design:

• The study sample comprised 127 elementary and middle schools, randomly assigned to get the program starting in 2016-2017 school year vs. 2017-2018 vs. 2018-2019. The study compared state test scores in ELA and math for students across the 3 groups who were screened as having vision problems.

• Importantly, vision correction offers many benefits (e.g., quality of life, safety). This study sought to determine if such correction, as delivered by the Baltimore program, could also increase academic achievement in a student population that was 80-90% Black and low-income.

Findings:

• Unfortunately, the study found no significant impact on either ELA or math scores on the state test (the primary outcome), after either 1 year (based on 3,170 students) or 2 years (based on 1,528 students). The effect sizes were all close to zero.

Comment:

• Based on careful review, this was a mostly well-conducted RCT (e.g., low school & student attrition, good baseline balance, pre-specified analyses).

• Disclosure: Arnold Ventures (AV), my former employer, helped fund the study. Here's AV's summary.

• The published study unfortunately doesn't make clear that the study's primary, pre-specified hypotheses were not supported, and instead highlights results (e.g., for subgroups) that are only exploratory and could be due to chance.