Are you clumsy? Do you have poor balance? Do you get car sick? These are all common problems when your eyes and middle ear having differences in information. Some people rely mostly on their eyes for controlling balance.
If your eyes are being fooled, and they are telling your brain that you are moving, and your middle ear is saying that you are not moving, this can confuse your balance. Likewise, if your ear says you are moving, and your eyes say you are not, this can create confusion as well.
Below are some demonstrations:
If an image moves across your vision it can be perceived as moving if the eye remains stable. If an object moves, and your eyes and head track it, this also will give the perception of movement. If a target is stationary, and your eye moves past it no movement will be perceived. If a stationary object is viewed, and your eye is moved without the brain sensing it, the image will appear to have moved. One way of tricking the brain is to view an object with one eye open. Lightly press the bottom lid of the open eye so the eye moves, the object will appear to move.
One example of this is the Auto kinetic Effect. This is the illusion of movement of a stationary point of light viewed in a dark field. To observe this illusion, you need a very dark room. No stray light should be present in the room. Next you need a small dim light (a lit cigarette works great). Place the light about 2 meters away from you and watch it. After a few minutes it should appear to move. This is due to small movements of the eyes that are not monitored by the brain. Everyone has some eye drifting. This means that when you look at an object, it is difficult for the eyes to maintain steady and accurate fixations. The visual system does not monitor the drifting eye movements, so the brain doesn't think the eye is moving, but the image is.
The visual system can be trained to rely more on the middle ear for balance, and less on the visual system. Try standing on one foot. Once you get your balance, close your eyes. Did you tip over? I bet you did. This demonstration shows just how much we rely on our vision for balance.