PUPIL, 



aiid. in tills fituation, aii ov<tl aperture is produced, through 

 whicli the rays of liglit pafs into the eye. A complete 

 clofure of the pupil is ufually the confequence of fuch de- 

 tachment of the iriS. A blow on the eye, a kick of a horfe, 

 or fome other external violence, attended with a violent 

 concuffion of the eye, is the common caufe of this detach- 

 ment of the iris. Janin has feen it brought on by a pro- 

 lapfus of the iris through an ulcerated opening in the cornea. 

 The iris was kept in a ftate of tenfion, and the patient was 

 fuffering conftant pain in the eye ; but, after a time, this pain 

 fuddenly ceafed, when it was remarked, that the iris was 

 torn from the upper edge of the cornea at five different 

 points. The patient, who had been deprived of his fight 

 by the clofure of the pupil, uovv recovered it again. 

 Tlirough the aperture, formed by a feparation of the iris 

 from the cornea, patients commonly fee dillant objefts 

 tolerably well, notwithftaiiding the opening is immoveable, 

 and not in the centre ot the eye ; but, in general, they can 

 fee only a half of fuch objefts as are near. In cafes where 

 the iris is thus detached, the pupil fometimes continues open. 

 Janin once noticed an alternate motion in the pupil and 

 the preternatural opening. Between them the iris was 

 thrown into folds, or wrinkles. Immediately a ilrong light 

 entered the eye, the wrinkles diminilhed, the pupil con- 

 trudled, and affumed a long narrow Ihape, while the preter- 

 natural opening grew larger and wider. In dark places, 

 the latter became fmaller, the pupil larger, and the part of 

 the iris fituated between them more wrinkled. 



Sometimes the pupil becomes clofed, in confequence of a 

 fpafmodic contraftion of the iris. At firlt, the pupil is 

 merely leflened in diameter ; the power of feeing decreafes ; 

 and at length the eye is very fenfible of the light, though 

 not at all inflamed. At lalt, the pupil is entirely clofed. 

 This cafe prefents itfelf mod frequently after operations for 

 the cataraft. The pupil occafioually undergoes a gradual 

 diminution after fuch operations, and in the end is totally 

 obliterated, without any particular caufe, inflammation, or 

 pain ; and this event may happen feveral weeks, months, or 

 years, after the time of thofe operations. It is remarked 

 Ijy furgical writers, that fuch perfons as frequently read for 

 a long while, and attentively look at (hining, bright, flrongly 

 illuminated objetts, run a ri(l< of being attacked with this 

 diforder. The pupil, which contraSs itfelf very much 

 during the infpection of thefe objefts, at length becomes 

 habituated to a Hate of contraftion, and lofes all power of 

 expanding itfelf. Richtcr obferves, that this form of the 

 complaint is lermed. fynl'z.efis ex coiifueludine. 



Infants are lometimes born witliout pupils. In this cafe, 

 the fituation oi theie openings is occupied by the membrana 

 pupillaris. By fome tliis affeftion has been erroneouHy 

 called cataraila pupiUaris : as Richter obferves, the term 

 fynh.'fis congenita is much more applicable to it. A pro- 

 l.ipfus of the iris is commonly attended either with a dimi- 

 nution, or a total clofure of the pupil. When the iris is 

 reduced in time, the pupil geiierally expands again ; but 

 when the reduction is not effeftcd till after a certain period, 

 this opening remains clofed, and this notwithftantling every 

 portion of the iris be now replaced. A prolapfus of the 

 ■vitreous humour fometimes occafions, and leaves after it, a 

 contrafted Hate of the pupil. E?ery long continued de- 

 ficiency of the aqueous, or confiderable lofs of the vitreous 

 humour, by whatfoever caufe produced, is accompanied 

 with nlk of a permanent diminution, or even a total clofure 

 «f the pupil : hence it is often a fymptom of atrophia oculi. 



Sou.etimes, though the pupil is of proper dimenfions, it 

 13 obftrufted by extraneous matter. This cafe is termed 

 fynizijit fpuria. The fubilance producing the obitruftion, 



is either a portion of coagulated blood, which is t!ie conlc- 

 quence of an extravafation of this fluid in the anterior cham- 

 ber ; thick matter from a fuppuration within the eye ; or 

 the remains of a difeafed lens continuing after the operation 

 of extrafting the cataraft. A white opaque membrane, 

 like a cyll, is fometimes feen protruding through the pupil 

 into the anterior chamber. The capfular cataraft is occa- 

 fioually fo moveable, that, when the head is inclined for- 

 wards, it enters the pupil, and partly comej into the an- 

 terior chamber ; but returns into its former pofition, as foon 

 as the head is inclined backward again. Mauchart afTerts, 

 that he has feen a fungous excrefcence grov/ing from the 

 edge of the iris, and filling up the pupil. 



When the diminution or clofure of the pupil is of long 

 Handing, it can never be relieved, except by an operation, 

 whatever may be the nature of the caufe from which it ori- 

 ginates. When the pupil has been for a long while in a di- 

 miniflied or clofed Hate, it lofes entirely the power of ex- 

 panding again, and continues leffened, or (hut, notwith- 

 flanding the removal of the caufe of the diforder. If the 

 affedlion be congenital, or the confequence of inflammation, 

 it can never be obviated except by an operation, however 

 fhort the period of its duration may be. When it arifes 

 from irritation of the iris, or from intenfe obfervation of 

 (hining, bright objefts, and has not exilled a long time, it 

 may be cured without an operation. Alfo, in cales wherj 

 the operation is necelTary, the mode of performing it differs 

 according to circumftances. 



Patients who become afflifted, in confequence of fre- 

 quently obierving bright, glittering objefts, may obtain 

 rcliuf by a timely avoidance of every light that is too ilrong, 

 wearing green fprAacles, viewing objedls with an opera 

 glafs, and frequently wafhuig the eye with fome warm 

 emollient liquor, efpecially a decodlion of mallows, hem- 

 lock, and poppy-heads. The peculiar virtue of the extra£l 

 of belladonna, in making the pupil dilate, might here alfo 

 be turned to great advantage. It is to be diluted and 

 rubbed over the eye-lids and eye-brow, and allowed to re- 

 main applied a certain length ot time every day. The fame 

 means are likewife proper in cafes, where the diforder de- 

 pends upon irritation. Richter fpeaks favourably of the 

 good eifefts of antimonial wine, and the extraft of aconi- 

 tum, as internal medicines, together with warm bathing 

 and blifters. Here the outward application of the extract 

 of belladonna unqueftionably merits a careful trial. 



Tliere is a preternatural contraftion of the pupil, which 

 alternately arifes and then ceafes again. This cafe fome- 

 times lafls only a few hours ; fometimes feveral days. 

 During the attack, patients fee more weakly than ufual, or 

 cannot fee but very little, according as the pupil happens 

 to be more or lefs dimini(hed. In particular mflances, the 

 attacks come on at fixed times, and the complaint is then 

 periodical. During the diforder, the pupil feems to be 

 afiedled with fpafm. Occafioually, indeed, fpafmodic com- 

 plaints, fays Richter, take place at the fame time in other 

 parts. Here the difeafe is moft commonly the confequence 

 of irritation feated in the abdominal vifcera, and requires 

 aperient, and efpecially emetic medicines. When thefe 

 means prove ineffectual, it is at length neceffary to refort to 

 the external and internal ufe of anodyne tonic remedies, 

 valerian, bark, and fmall dofes of ipecacuanha. The out- 

 ward application of the extraft of belladonna to the eye- 

 brow and eye-lids promifes alfo, in fuch cafes, to be an 

 ufcful auxihary means. This fort of clofure of the pupil 

 has been obfervcd as a fymptom of hyfteria. 



The eminent Mr. Chefelden firft made the propofal of 

 perforating the iris, and alfo firil put fuch an operation in 



7 execution. 



