If the child is still experiencing tearing after 3-4 months of age, a tear duct exploratory procedure is recommended. Lacrimal duct obstruction is usually caused by the underdevelopment of the lower end of the nasolacrimal duct after birth, which does not fully form the canaliculus, or by the blockage of the mucosal folds of the lower end of the nasolacrimal duct at birth, which leads to tearing. In most children, the lower end of the nasolacrimal duct will heal on its own, or with the aid of some localized massage. Massage method is to put the index finger on the lacrimal sac area, regular massage and pressure, 3-4 times a day, more than 20 times each time, adhere to the lower end of the nasolacrimal duct will be open after a few weeks in most patients, tearing symptoms will be eliminated. If conservative treatment is ineffective, and the child reaches the size of 3-4 months, the possibility of late self-healing or opening is relatively small, at this time you need to go to do tear duct probing. This is because if the child is too old, the lower end is tougher and the probing is less likely to be successful.