When mutations happen on bilateral structures, they happen bilaterally. Haven't you ever seen anyone with the second and third toe fused. It will happen on both sides. You do realize that all the cells in the body come from the same cell with the same mutations, right? The mutation for blue eyes makes both eyes blue.
The mutation that causes the most common forms of dwarfism affects the long bones of the arms and legs. All of them. It's not one limb affected per mutation. In affects all the place where collagen should grow and then turn to bone. A single change messes up the whole program and you end up with dwarfism.
I think you are way, way, way out of your league here.
If your questions aren't answered in the manner you asked, it might be because no one realized how very ignorant you are on the subject.
If you have a mutation for red hair... it doesn't just make one hair have red pigment! And yet your tear duct question seems to be on par with the red hair example. I think you need to start at the very beginning and start getting your science from scientists rather than self-appointed experts in undetectable realms. You have some very knowledgeable people here who will give you lessons tailor made for you, but in order to understand them, you'll need to quit imagining you know more than them already.
Edited by articulett, : provide further examples.