• Maternal drug abuse during pregnancy exposes the fetus to the possibility of toxic or addicting effects. At a methadone hydrochloride maintenance program providing medical care to drug-dependent women and their infants, ophthalmologic examinations of all infants born during a 36-month period were performed. Twenty-nine infants prenatally exposed to psychoactive drugs were seen at birth and on follow-up. The 24% prevalence of strabismus found in the drug-exposed infants was significantly greater than that of 2.8% to 5.3% reported in the general population. These data suggest that maternal drug abuse and increased methadone dosage during pregnancy may predispose infants to the development of strabismus.