To test an educational intervention's effect on improving detection of glaucoma by direct ophthalmoscopy, 14 medicine residents examined five patients, two with ophthalmoscopic changes of glaucoma and three with normal fundi. The residents observed a standardized slide/narrative educational intervention reviewing glaucomatous ophthalmoscopic changes and then re-examined the same patients eight to 12 weeks later. The intervention's odds of improving residents' diagnostic impression were significant (OR = 2.2; 95% CI = 1.3-3.6), with significant improvement in sensitivity (p = 0.02) and a trend toward improved specificity. These findings confirm that the diagnosis of glaucomatous ocular changes on eye examinations by medicine residents can be improved with a brief educational intervention.