The human eye : its optical construction popularly explained / by R.E. Dudgeon.

  • Dudgeon, R. E. (Robert Ellis), 1820-1904.
Date:
1878
Catalogue details

Licence: Public Domain Mark

Credit: The human eye : its optical construction popularly explained / by R.E. Dudgeon. Source: Wellcome Collection.

    24/132 (page 8)
    through the lens in a straight line, and as it emerges from the opposite side of the lens at H, perpen- dicularly to the surface of the less refractive medium M, whose shape is determined by that of the lens, the ray still goes on in a straight line. But the ray B impinges on the surface of the lens L obliquely at E Fig. 4. M a u M B E Ad,.'- / A Sj...--' D : H C M L M (R Q is the prolonged radius of the surface L E L, and BEQ is the angle of incidence of the ray B), and as L has a greater refractive power than the medium whence the ray comes, the ray is now in its passage through L deflected towards the perpendicular of the surface E of the lens. The radius R E of the convex surface L E L of the lens, is the perpen-