Sight: An Exposition of the Principles of Monocular and Binocular Vision

actual adjustment already angle animals appear becomes binocular binocular vision bring brought called central spot circle clear colors combined complete condition cones convergence corresponding points cross diagram direction distance distant objects distinct double images evident exactly Experiment explained external fact fall farther field of view figures front give half horizontal horopter Illustrations impression inches inclination increasing judgments kind layer left eye lens less light limit look median middle motion move muscles natural nearer necessary nerve nose object observer opposite optic axes outward parallel passing perceived perception perfect perfectly perspective phenomena plane point of sight position primary produced projection rays referred represent result retina retinal images right eye rotation screen seen shown side single space stereoscope structure surface tion true turn unite vertical vision visual lines visual result wall whole