On the anomalies on accommodation and refraction of the eye : with a preliminary essay on physiological dioptrics / by F. C. Donders ; translated from the author's manuscript by William Daniel Moore.

Franciscus Donders

Date:: 1864

Credit: On the anomalies on accommodation and refraction of the eye : with a preliminary essay on physiological dioptrics / by F. C. Donders ; translated from the author's manuscript by William Daniel Moore. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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$SIGNS AND ABBREVIATIONS USED IN THIS WORK p, radius. P°j radius of the cornea in the visual line. n, coefficient of refraction. k, nodal point. h, principal point. k! and k, anterior and posterior nodal points of the same system. h' and h, „ „ principal „ „ 9' and 9, „ „ focal kx and k2, two nodal points of two different systems. hx and h2, „ principal „ „ ¥1 and 92, „ focal „ 0, optical centre. F' and F, anterior and posterior principal focal distances. F, principal focal distance where F' and F are equal. /' and/, conjugate focal distances calculated from h' and h. B, an object; p, its image. i, a point in the axis; j, its image. i', a point outside the axis; j', its image. p} (proximum) absolute nearest point of distinct vision. Pi> ( » ) relative p2, ( „ ^ ) binocular „ „ „ r, (remotissimum) absolute farthest point of distinct vision. rl5 relative r2, binocular „ „ „ P/5 P]? and P2, distances from pp px, and p2 to k'. R, R1?andR2, „ rt9 r„ and r2 „ P' P, and R' R, „ and from r to a lens or another given point. 1 : A, absolute range of accommodation. 1 : Al5 relative „ „ 1 : A2, binocular „ O, the eye; D or R, right; S or L, left. C, the cornea. L5 crystalline lens. a lens. N, the retina. V, the vitreous humour. D, the thickness of a lens. x, distance of a lens from a point. a, angle between visual line and axis of the cornea. S, acuteness of vision. E, Emmetropia.$