Anatomy and physiology of the eye, with hints for the preservation of the eyesight (1901)
Herbert, John Frederick, 1860- · Philadelphia, Pa., The author · leaf 57
e focus, F, is situated on the same sideof the lens on which the object lies ; F would be at thatpoint at which the diverging rays cross one another if theywere continued backward. This is called the virtualfocus. Hence the more divergent the rays are after theirpassage through a concave lens the… … Fijfure 32. Prismatic lenses displace objects ill llie (lireciioii of the apex, or edge. The light L, which is situated directly on a level with the eye, appears to come from the direction of the dotted line. meet at a point situated more remote from the lens. Con-cave lenses are numbered and…
Eye · Lenses
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