Scientific amusements . Hypermetropia (long sight). F in the diagram. But converging rays falling on itemerge in a parallel direction as on page 123, or divergeas in the second illustration on page 124. The use of spectacles to long or short-sighted peopleis a necessity, and the lenses used vary. The eye has. Myopia (short sight). usually the capacity of suiting itself to viewing objects—its accommodation, as it is termed—near or far. Butwhen the forepart of the eye is curved, and cannot adaptitself to distant objects, the person is said to be short-sighted. In long sight the axis of the eyeba
Scientific amusements . Hypermetropia (long sight). F in the diagram. But converging rays falling on itemerge in a parallel direction as on page 123, or divergeas in the second illustration on page 124. The use of spectacles to long or short-sighted peopleis a necessity, and the lenses used vary. The eye has. Myopia (short sight). usually the capacity of suiting itself to viewing objects—its accommodation, as it is termed—near or far. Butwhen the forepart of the eye is curved, and cannot adaptitself to distant objects, the person is said to be short-sighted. In long sight the axis of the eyeball is tooshort, and the focus falls beyond the retina; in shortsight it is too long. In the diagrams herewith (see above) 126 OPTICAL APPARATUS, the first shows by the dotted lines the position of theretina in long sight, and in the second in short sight,the clear lines showing in each case the perfectly-formedeye. For long sight and old sight the double-convexglass is used, for short sight the double-concave. Weknow the burning-glass gives us a small image of
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Keywords: ., bookcentury1800, bookdecade189, booksubjectscientificrecreations
