What is Listing's Law?

• Donders' law states that the orientation of the eye when looking in a specific direction is always the same.
• Listing's law specifies what this orientation is.
• Note the axes (the bars protruding from the eyes) used to rotate from center to various eccentric positions.
• Listing correctly predicted that all these axes are confined to a common plane.
• This plane is called Listing's plane.