Rabbits were continuously administered copper sulfate via subcutaneously implanted osmotic pumps. After one month, plasma, liver, ocular tissues and fluids were analyzed for copper by atomic absorption spectrophotoraetry. No elevation in copper content of the ocular fluids, lens or iris was noted although, dose-related increases were seen in the plasma and liver indicating that the copper was absorbed and disseminated systemically. It is likely that excess copper, like that which is normally ingested and absorbed, is largely protein-bound in the circulation, preventing crossing of the blood-ocular barrier.