Suggest Treatment For Blocked Tear Duct In Infant

My baby is 12 weeks old and was born with blocked tear duct. 3 days ago his eyelids were red and swollen. I was told by a GP that my baby had conjunctivitis. He subscribed antibiotic eye drop called Tobrex which had been used for the past 3 days. In consulted an paediatric eye doctor later and was told my baby has a condition called naso lacrimal duct obstructive and another eye drop Fucithalmic was subscribed for the use of one week. Are there any side effect on young babies with all those eye drops? Will it cause any vision problems?