Congenital nasolacrimal duct obstruction (CNLDO), previously considered a benign disease, affects 20% of the children globally. It is described by a collection of symptoms in which continuous epiphora and intermittent discharge are present in either one or both the eyes. CNLDO usually resolves in most healthy infants in the first few couple of months; however, it may persist for a number of years in some children. There has been a lot of recent deliberation on how a constant watery eye affects the visual development during the phase of emmetropization in children. A connection between CNLDO and anisometropia has been hypothesized. Multiple factors which include developmental and environmental aspects are thought to play a contributory role in the development of anisometropia by and large; particularly hypermetropic anisometropia, raising the chances of developing amblyopia in children with CNLDO. Published literature on CNLDO had shown inconclusive evidence on this anecdotal propinquity. This chapter discusses CNLDO; etiology, pathogenesis, treatment modalities, surgical intervention, and its role in inducing refractive errors; and its propensity to cause amblyopia.