A treatise on the diseases of the eye . n or uvea in the other. The changes now described must necessarily affect the figure and mo-tions of the pupil. It is generally contracted; and it may exhibit everyvariety of form, being in different cases oval, angular, shaped like an hour-glass, stellated, or otherwise irregular. Mere alterations of figure are notinjurious to vision; which is just as good with the most irregularly shapedpupil as with a circular one; and we often see perfect vision with great andpermanent contraction of this aperture. It must be understood, of course,that the retina is
A treatise on the diseases of the eye . n or uvea in the other. The changes now described must necessarily affect the figure and mo-tions of the pupil. It is generally contracted; and it may exhibit everyvariety of form, being in different cases oval, angular, shaped like an hour-glass, stellated, or otherwise irregular. Mere alterations of figure are notinjurious to vision; which is just as good with the most irregularly shapedpupil as with a circular one; and we often see perfect vision with great andpermanent contraction of this aperture. It must be understood, of course,that the retina is uninjured, and that the pupil, however irregular or small,is clear. By the adhesions now described, the motions of the iris are im-paired or entirely lost. Adventitious membrane in the pupil.—If the lymph thrown out intothe pupil, and lying on the crystaline capsule, be not soon absorbed, itbecomes organized, and forms an opaque adventitious membrane adherentto the capsule and to the pupil, and corresponding in size to the dimen- 393. sions of the pupil at the time of effusion, (fig. 58.) The opacity ofthis new production is greatest in the centre, and gradually shaded offtowards the circumference. In the contracted state of the pupil, it fills Fig. 58. the old aperture; but when theedge of the iris is withdrawn, it issurrounded, partially or entirely, bya clear black margin, and the iris isfound to be attached to it by oneor more adhesions, which may beeither close, or in the form of shortblack or whitish threads. These ad-hesions sometimes divide, the clearportion of the pupil into small round-ish or irregular apertures. In suchcases, the pupil does not change un-der variations in the quality of light; it is usually necessary to apply bella-donna in order to expose the clear part of the opening, and the adhesionswhich connect its margin to the adventitious membrane. If the effusion shouldhave occupied the pupil and margin of the iris only partially, the adventitiousmembrane
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Keywords: ., boo, bookcentury1800, bookdecade1840, booksubjecteye, bookyear1847
