OBJECTIVE: To determine the effectiveness of an online video intervention in improving self-efficacy and eye drop application technique in glaucoma patients. METHODS: We randomized ninety-two patients with primary open-angle glaucoma, all who self-administer their eye drops, to either watch the 4-minute Meducation® eye drop technique video in the intervention group, or a nutrition video in the control group. We assessed five eye drop technique steps using objective video recordings at baseline, immediately after watching the video, and 1 month later. We used linear regression models to determine whether the intervention group had better self-efficacy and technique than the control group. RESULTS: Adjusted for baseline technique and other covariates, eye drop technique averaged 0.73 steps better in intervention patients than controls immediately after the video (p = 0.003) and 0.63 steps better at 1 month (p = 0.01). Adjusted for baseline self-efficacy, intervention patients had better eye drop technique self-efficacy than controls immediately after the video (p = 0.02) and at 1 month (p = 0.02). CONCLUSION: A short educational video can significantly improve glaucoma patients' short-term self-efficacy and eye drop technique. PRACTICE IMPLICATIONS: Videos may provide an inexpensive, convenient way to deliver eye drop technique education in any provider's office or online.