Too many tears: Sometimes the eye makes more tears than it can drain. A dry, irritated eye is one of the commonest triggers – the dry surface floods itself with reflex tears. Here the answer is in treating the dry eye.
Poor drainage: The tears are normal, but the “water pipe” that carries them away — from the inner corner of the eye, down into the nose is blocked. This is the situation a DCR is designed to fix.
In babies: Many babies are born with a membrane still closing the lower end of the tear duct (congenital nasolacrimal duct obstruction). This causes watering and sticky discharge.
The reassuring news: most clear on their own within the first year, helped by a simple tear-sac massage technique. If the blockage persists beyond about a year, a quick probing procedure opens the duct.

A DCR creates a new passage for tears to drain from the tear sac directly into the nose, bypassing the blocked duct. There are two approaches to surgery:
Scarless (endoscopic / endonasal) DCR – performed entirely through the nose using a fine endoscope, with no incision on the skin and no visible scar. Recovery tends to be quicker, and more pain-free.
External DCR – a time-tested approach through a small incision near the inner corner of the eyelid, which heals to a faint line that is easily concealed. For certain blockages it remains the best choice.
Both approaches have high success rates, and in some cases a soft silicone tube is placed temporarily to keep the new passage open, removed after one month.