The lacrimal duct is a delicate tube leading from the eye to the nasal cavity and is responsible for draining tears from the eye to the nasal cavity. Our tears are continuously produced to clean and moisten the surface of our eyes. But we do not show “teary eyes” because the tears flow to the nasal cavity through this delicate tube. This is why some people feel a bit bitter in their throat after using eye drops, because the eye drops flow from the tear duct to the nasopharynx. In the embryonic stage, the tear duct starts out as a solid column of cells. During embryonic development, the cell column becomes vacuolated and slowly evolves into a cavernous duct that takes on the task of draining tears, the lacrimal duct. The completion of vacuolization can occur before birth or can continue up to 1 month after birth. During development, if the tear duct vacuolation is incomplete or if there are other developmental abnormalities that affect the patency of the tear duct, it can cause tear duct obstruction. Tear accumulation in the tear sac, poor drainage and secondary infection can lead to the formation of dacryocystitis.