The true threshold of the slow nystagmic component-L

The fast component of nystagmus begins where the slow component stops, at the point called the threshold of the fast component R. The fast component should last until the eye is brought back into the position of azimuth zero, where the slow component begins anew. This point can be called the threshold of the slow component L. So the fast component has a span from R to L and is presented as a side of a triangle r. An additional corrective procedure in electronystagmography is suggested to avoid failures and to define the true position of L. This is the way to correct the false information on nystagmic elements and to learn the unknown features of the fast component.