Gun sights are well known in the art and encompass a variety of types. Generally, gun sights comprise a front sight member and an axially spaced rear sight vane, and the user visually aims the gun by aligning his line of sight between the rear sight vane, front sight, and the target. However, a common problem for a user of any of these variety of visually aimed gun sights is the effect of parallax. Parallax is the apparent displacement, or the difference in apparent direction, of an object as seen from two different points not on a straight line with the object. Often, an object will appear to shift position when viewed from two different points not on a straight line with the object.
A user will commonly experience the effect of parallax when visually aiming a gun when the user has both eyes open. The vision of the user's non-aiming eye may interfere with the vision of the user's aiming eye, and because each eye is located at a different point not on a straight line with the target this causes the target to appear to shift while aiming the gun at the target.