Yes, the blocked tear duct may cause your lazy eyes. Although most lazy eyes are born to be or be developed in the growing age, lazy eyes could also be caused by the bad use of eyes and other eyes problems. The blocked tear duct will affect the vision because of the disorder of the tear excretion system. That is why it causes the lazy eyes. You should treat the lazy eyes in time.
Tear duct blocked is a really upsetting problem. You might have excessive water from eyes and a green-blue pus secreted in eyes. It is rather annoying and embarrassing. Usually in infantry, the blocked tear duct is congenital. While in adults, it might be caused by infections or nasal problems. Yet it brings no other harms or more serious eye problems. Lazy eyes are usually caused by significantly unequal diopter of two eyes or strabismus referring to ocular misalignment. There is no way to get lazy eye from tear duct clogged. Don't worry about it. As to blocked tear duct, you can apply some warm saline water to reduce the inflammation. Use the saline water to wash eyes, so that the pus and crust can be cleaned. Some massage at the corner near to eyes could effectively help break the blockage although it might bring some discomforts. Usually it takes weeks to heal up.