A blocked tear duct in a baby could present with too much tearing at 6–8 months old.
Frequently, narrowing of the nasolacrimal duct may lead to enlargement of the sac immediately above. This may cause mucous build-up, with repeated eye infections, smeary vision, and ‘gummy’ eyelids. Also, it could cause an infection of the sac itself and a painful lump in the inner corner of your eye, called dacryocystitis.