The practice of physick in seventeen several books wherein is plainly set forth the nature, cause, differences, and several sorts of signs : together with the cure of all diseases in the body of man / by Nicholas Culpeper ... Abdiah Cole ... and William Rowland ; being chiefly a translation of the works of that learned and renowned doctor, Lazarus Riverius ...

CHAP. VI. Of the straitness, or Contraction of the Pupilla.

THe Pupilla being too straight, hindereth the sight, as the being of it too large, as was shew∣ed in the former Chapter, because a moderate largeness of the Pupilla is necessary for recei∣ving perfectly the visible Species. So when the Eye is in its Natural condition, and is in a light place, the Pupilla is contracted lest it should take in too much light, if suddenly it be in a dark room, the things therein contained are little or scarcely seen at the first entrance, by reason of the aforesaid contraction. Afterwards when the Pupil is dilated, al things are seen rightly, there∣fore in a place moderately light, the breadth of the Pupilla ought to be moderate, that it may receive moderate light, not too much, nor too little, for making a perfect sight. But if the Pupilla be too narrow, it receiveth not light enough, therefore they who are so affected, the sight is diminished, yet they see well in a very light place, because at that time light sufficient will pass through a narrow hole, if no other Disease of the Eyes be joyned with it.

Now the narrowness of the Pupilla, cometh either from the original, or first constitution, and then it little hindereth; for if they who are so affected see less in a dark or dusky place than they who have a Pupilla of its moderate natural breath, yet in a clear light place they see better. Hence Galen said in 1. de symp. caus. cap. 2. that they who are born with smal Pupilla's see best.

Or the straightness of the Pupilla comes from preternatural causes, namely, overmuch moisture, driness, or defect of the Watery Humor, and want of Spirits.

The Pupil is contracted by humidity, when the Uvea is relaxed, and so makes the hole less or nar∣rower: For although the dilatation of the Pupilla come of the same humidity, yet contrary effects come not of the same cause, because if the cause may be called the same, it ought to have the same re∣••ation to its effects, but humidity is not in the same manner when it makes a Dilatation, for it makes ••hat by filling and distending the Membrane, but it makes the angustia or narrowness by relaxing it: 〈◊〉〈◊〉 relaxeth when it is united to its substance.

Concerning dryness there is the same difficulty, since it is mentioned among the causes of dilating ••he Pupilla. But this is the difference: When the Uvea is dryed, and the humors of the Eye re∣main

in their due quantity, then it makes a dilatation of the Pupilla, because it looseth not the extention which it formerly had, as was said in the precedent Chapter, concerning Skins extended when dryed, make their holes larger; but if the Tunicle Uvea when it is dryed, wrinckled, falls to∣gether, and loose its former extension, from the defect or diminishing of the humors of the eye, then is the hole of the Pupilla made straighter.

And so the constriction of the Pupilla by driness wil be almost the same with that which happen∣eth from a defect of the watery humor in the eye; although it may come without driness, when by the powring forth of the watery humor the Uvea falls down.

Lastly, she narrowness of the Pupilla comes from the defect of Spirits, or from the fewness of them, when by reason of the obstruction of the optick Nerve or some other cause, the visive spirit cannot come to the eyes, which when it is filled with spirit keeps its Tunicles extended; but when it wanteth spirits they grow lax and fal together: Hence the constriction of the Pupilla usually co∣meth. This appeareth in very Old men, in whom the Pupilla is made narrow by reason of the want of spirits.

This Disease is known easily being open to the sense, for if one eye alone suffer, by comparing it with the other you may perceive the straightness of the Pupilla; but if both suffer, by looking upon the eyes of another man who is sound sighted, you find it out.

As to the Prognostick, a straightness in the Pupilla which cometh from the loss of the watery hu∣mor in the eye, is incurable, because when that is once lost it cannot be recruited; especially in old folk: in yong people somtimes the watery humor of the eye hath been let forth by a wound, and hath been repaired again: A Constriction of the Pupilla from driness, can scarse, and very hardly be cured: But that which comes from moisture, in the beginning, and being yong, may be easily Cured: but an old one very hardly.

The Cure of this Disease differeth not from the former, for they come both from the same Causes, namely, Driness, or Moisture; which distempers, although they produce contrary effects, after the manner before Explained; yet are they to be Cured by the same Remedies.