Contact lenses move differently on eyes depending on their design. All contact lenses are meant to move on the eye to some degree, but how much a lens moves is determined by many different factors.1. Type of Lens 2. Fits 3. Tears 4. Oxygen 5. Blinking
Maybe it is because you can't put them into the correct position. If they are in the right position, it is probably caused by the bigger of basic curve. If the number of basic curve is bigger, then the lens is flatter and in this case the lens will slip so that you can feel the lenses moving in your eyes.