Aquired obstruction Primary punctal stenosis (chr.blepharitis,idiopathic primary stenosis,herpetic infection of eyelid,irradiation, cicatrizing conjunctivitis and trachoma,cytotoxic drugs, porphyria cutanea tarda,acrodermatitis enteropathica) Secondary punctal stenosis (punctal eversion) Canalicular obstruction(cong.,trauma,herpetic infection, drugs and irradiation,chr.dacryocystitis) Nasolacrimal duct obstruction (idiopathic stenosis, trauma,previous surgery,granulomatous disease, tumours) ·Dacryolithiasis Aquired obstruction • Primary punctal stenosis (chr. blepharitis, idiopathic primary stenosis, herpetic infection of eyelid, irradiation, cicatrizing conjunctivitis and trachoma, cytotoxic drugs, porphyria cutanea tarda, acrodermatitis enteropathica) • Secondary punctal stenosis (punctal eversion) • Canalicular obstruction (cong., trauma, herpetic infection, drugs and irradiation, chr. dacryocystitis) • Nasolacrimal duct obstruction (idiopathic stenosis, trauma, previous surgery, granulomatous disease, tumours) • Dacryolithiasis