You didn't mention breed or describe what you are seeing or why you ask so it's difficult to say. Most problems involving the eye involve treatment from a veterinarian to correct. Some problems that might be confused as a tear duct problem are; cherry eye (swollen gland which irritates the eye), entropian (rolled in eyelid irritating the eye), distichiasis (extra eyelashes growing inside the lid irritating the eye). Some breeds tend to be more prone to certain conditions than others. You should have it checked out by your vet to confirm whether or not it's a problem and what the treatment is. Wish I could have helped more.