Is this double vision?

For almost 2 years now, I've been seeing what i think is double vision. It's not very intense, like it doesn't get in the way of my everyday tasks but it bothers me when i notice it. When i look at an object (it doesn't happen with all objects, i haven't figured out why that is or with what objects exactly this happens because they don't have much in common) it's like the images perceived by both my eyes don't align. This photo is the best way to explain it. It's not that intense thought, it's waaaaay more subtle. Sometimes though, in chairs the difference can be up to an inch. Or for example, i saw a nail in a wall and i saw "another" nail right underneath it so it looked like two nails but i could tell which one was the real one. I've noticed that when i tilt my head back enough while watching the object it goes away. I've been to 3 different optometrists and done all the tests and they tell me my eyes are very good and they can't find the problem. One even thought i was faking it. I don't know what to do, i know that if i go to another doctor he'll tell me my eyes are fine too. How do i make it go away? What's wrong with me? Thank you for taking the time to read this.