Anisometropia was recently shown to develop in ten percent of infants diagnosed with dacryostenosis at a mean age of one year. The purpose of this study was to determine whether earlier (<1 year) spontaneous resolution or probing decreases or eliminates this risk. The medical records of all patients diagnosed as an infant with dacryostenosis from January 1, 1988, through December 31, 1992, were retrospectively reviewed. Anisometropia was defined as ≥1 D of refractive error between the two eyes. Among 662 consecutive infants, 244 (36.9%) subsequently underwent a complete ophthalmic examination: 189 (77.5 %) spontaneously resolved at a mean age of 4.5 months (range, 0.3-35 months), and 55 (22.5 %) underwent probing at a mean age of 16 months (range, 0-53 months). Anisometropia was diagnosed in 17 (9.0%) of the 189 who spontaneously resolved and in two (3.6%) of the 55 operated children (P = 0.19). There was a tendency, although not statistically significant, for earlier resolution to be associated with higher rates of anisometropia. Although dacryostenosis is associated with the development of anisometropia, especially among those with early spontaneous resolution, it remains unknown whether this relationship is causal or merely an association and whether early surgical intervention can modify or eliminate this risk. Early spontaneous resolution of dacryostenosis was more likely to have a higher, not lower, rate of anisometropia than late spontaneous or surgical resolution. Further studies are warranted to clarify the relationship between age at resolution and the development of anisometropia in infants with dacryostenosis.