Why are my eyes itchy and teary?

Dry eyes/Blepharitis: There are 2 major reasons for itchy & teary eyes. Most common is Meibomian gland dysfunction resulting in excessive oil in tear & Blepharitis. The 2nd most common cause is dry eyes; & often the 2 conditions co-exist. The reason you get tearing in dry eyes is that the basal tears are decreased & in reflex the tear gland which is for crying secrets & results in tearing.