Sometimes, when I close one eye, I see a ghost image with the other eye. When both eyes are open it doesn't happen. When only one eye is open, it usually doesn't happen either, except in specific circumstances, such as when I look at a thin white line on black background. In those cases, there is a ghost image. This is with my eyeglasses on. It becomes a bit worse when my eyes are dry.
Also, I went to an MD ophthalmologist about a month ago for an exam.