Why is it that when you stare at a stationary object for a long time it can appear as if its moving slightly?

No, I'm not crazy. I don't know if you have experienced this yourself, but if you stare at something for a really long time it almost looks like its slightly moving. Does anyone know why this is?Why is it that when you stare at a stationary object for a long time it can appear as if its moving slightly?
This is because it is YOU who starts to move - not the object.Why is it that when you stare at a stationary object for a long time it can appear as if its moving slightly?
Your eyes are focused and by fixing the image they move making the brain think it's moving. Thats what i've been told
i would say its either:


1) you are moving yourself...


2) you expect the object to move hence your brain makes you think it does......


or 3) your eyes are working to focus on the one object, but dont forget you have 2 eyes which one eye sees a different point of view than the other. Even with just a slight adjustment from either or both eyes there will be a shift in your view... and this will occur because your eyes are not stationary unlike a microscope lens or something.