We studied the rate of failure to use eyedrops as prescribed for glaucoma and some of the factors possibly associated with that noncompliance by interviewing 100 patients being followed in a setting emphasizing correct usage. Fifty-nine reported they had not used their eyedrops precisely as prescribed. Factors significantly influencing compliance included daily dose frequency, forgetfulness, inconvenience, and unaffordability. Gender and race were marginally significant factors, with men and blacks reporting somewhat higher rates of missed doses than women and whites. Side effects and age were not significant causes of noncompliance.