 The pitch of a parallax barrier should ideally be roughly two times the pitch of the pixels, but the optimum design should be slightly less than this.This perturbation to the barrier pitch compensates for the fact that the edges of a display are viewed at a different angle to that of the centre, it enables the left and right images target the eyes appropriately from all positions of the screen.In a parallax barrier system for a high-resolution display, the performance (brightness and crosstalk) can be simulated by Fresnel diffraction theory.