Introduction In medicine, patient adherence refers to the degree to which a patient correctly follows medical advice, and it most commonly pertains to medication or drug compliance. Patient adherence to glaucoma treatment has been a frequent and serious issue that is associated with adverse long-term outcomes. The purpose of this study was to determine the factors that are associated with adherence to glaucoma treatment among patients during the ongoing coronavirus disease 2019 (COVID-19) pandemic. Methods This was a cross-sectional study involving 100 consecutive glaucoma outpatients who were interviewed based on the modified version (ARMS2-COVID) of the original Adherence to Refills and Medications Scale 2 (ARMS2) that examined adherence to medication. Length of treatment and disease onset along with basic demographic details (gender, age, socioeconomic status, and educational levels) of the patients were also recorded. Results The COVID-19 pandemic has disproportionally impacted patients of older age (p=0.033) and lower educational levels (p<0.001) with regard to their ability to follow their treatment plan regardless of the duration of previous treatment. Conclusions Based on our findings, in order to ensure higher levels of patient adherence among patients of older age with limited education, more planning will be required, aided by appropriate educational interventions and proactive patient follow-ups., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2021, Mylona et al.)