This test is used to measure latent, manifest, horizontal, vertical, or torsional strabismus for distance and near fixation using a double Maddox Rod method in a trial frame. The lenses provide one color line image to one eye and another color line image to the other eye. The deviation between the two light lines is measured using Prisms. The kit includes a red, white, and green Maddox lens with a disposable penlight.