. Refraction and how to refract : including sections on optics, retinoscopy, the fitting of spectacles and eye-glasses, Fig. 142.—Illustrating High Myopia with a Concave of light from the lamp (L) are reflected by the mirror (w), and fonn aconjugate focus at L, and the rays from this focal point illuminate theretina at L^. Con-esponding effects result when reflection takes placefrom the mirror at m. The eye (E) behind the mirror recognizes pointsof reversal between the eye and mirror, moving in the same direction tothat in which the mirror is Fig. 143.—Illustrating H
. Refraction and how to refract : including sections on optics, retinoscopy, the fitting of spectacles and eye-glasses, Fig. 142.—Illustrating High Myopia with a Concave of light from the lamp (L) are reflected by the mirror (w), and fonn aconjugate focus at L, and the rays from this focal point illuminate theretina at L^. Con-esponding effects result when reflection takes placefrom the mirror at m. The eye (E) behind the mirror recognizes pointsof reversal between the eye and mirror, moving in the same direction tothat in which the mirror is Fig. 143.—Illustrating Hyperopia with the Concave eye (E) recognizes a virtual image behind the eye under examination, sothat when the mirror {in) is focusing the rays from the lamp (L) at L,the upper portion of the retina is illuminated, and vice versa, when themirror {m) is focusing the rays at Lj) the lower portion of the retina isilluminated. The retinal illumination moves opposite to that of the mirror. the right hand before the right eye, so that the sight-holeis opposite to the observers pupil. The movements im- l6o REFRACTION AND HOW TO REFRACT. parted to the mirror must be limited, though they may bequick or slow, but never at any time should the mirror betilted more than 2 or 3 mm., otherwise the light will be lostfrom the eye. What the Observer Sees, or the general appearanceof the reflection from the eye.—The reflex from the pupilvaries in different patients, and is subject to many changesas the refraction is altered by correcting glasses, by theturning of th
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