5 week old with crusty eye?

I noticed this morning one of my five week old twin girls had a crusty eye when we got up. I used a warm cloth and wiped it away. However, it continues to produce a small amount of yellow goop. Her eye itself isn't red but it keeps getting crusty.

Google seems to suggest this is a blocked tear duct and I'm going to call the doc in the morning. Ive been gently massaging the area and put a bit of breastmilk in the corner. But anyone else gave any ideas? It doesn't seem to be bothering her but as a FTM it's stressing me out.

Update: boob milk is magic apparently ;) her eye is all fixed up today!