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

angle axis bacillary layer binocular perspective binocular vision blind spot central spot color-blind color-substances colors combined image concave corresponding points cross depth of space distance distant objects distinct double images evident exactly Experiment external images farther fibers field of view figures finger fore halves Helmholtz heteronymous homonymous horizontal horopter horopteric line Illustrations impression inches inclination interocular space inverted jects judgments left eye left-eye image lens light line of sight look median plane monocular motion muscles naked eyes nearer normal eye nose oblique observer ocular optic axes optic chiasm optic nerve outward parallel perceived perfect perfectly phantom phenomena point of sight position projection ray-line rays represent retina retinal images right and left right eye rotation screen seen single sensation shut side single vision spectral stereoscope surface theory tion torsion turn the eyes vergence vertical lines vertical meridian vibrations visual plane visual result vitreous humor wall yellow