OPTICAL OUTLINES. 27 from oU , and toward this point the eyes will be directed, though the object still remains at ob. The same effect is given by a single prism of twice the strength before one Fig. 16. … Effect of prisms in lessening convergence. <6 eye, though the actual movement is then limite^TO the eye in question. If spectacle lenses be placed so^ftiat the visual lines do not pass through their centres j&gy act as prisms, n varies with the though the strength of the prismati power of the lens…
Eye—Diseases · Color blindness · Eye Diseases · Color Vision Defects
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