Visual Phenomena


IT is evident A. Mallock (vol. xiv, p. 351) and H. Airy (p. 392) describe two different, though allied, phenomena; the latter describes the appearance of rays of light, which, after entering the eye, meet at a focus, and diverge before reaching the retina; and the former, that of rays which reach the retina before meeting at a focus. For convenience, I shall call these respectively the “over-refracted radiance” and the “under-refracted.” They differ in the following particulars in the case of my own eyes:—

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BACKHOUSE, T. Visual Phenomena. Nature 14, 474 (1876).

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