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Show 884. Of the Eyes. BOOkIIL Book III. he Pu il maketh its retreat, inward, toward the aqueous Humor of 0f the chr. 835» Thefe Proceiies borrow their Origen from the inward Region of the Pe- 7:30pm; rimcter, relating to the Meta, where it reficth upon the Cryilalline Humor, aiding". affix, it isii'ecollcé‘ted by narrowing it {elf to deny admiflion t0 the too troublefome addrefs of the brighter beams, into the chambers of the Eye, And [he Pupil is not only enlarged, to give a freeacccfs to fainter, and and are many minute Filaments or Fibres pafling into, and encircling the convex Surface of the Cryftalline Humor, tying it to the inward Surface of firefli'iriiii' 0‘ lefiened to give a denial to over-bright Rays, but With them to give a teception alfo to the vifible refemblances of outward Objects, .the one near, [he Mel/ea, and alfo thefe fine ProcefTes do infinuate into the Retina, drama, and Hylaoider‘, and being every way twined round the Cryfialline Humor, and the other remote, while we view the nearer, the Pupil is contracted; and when we fee the more remote, it is dilated, which is occafioned ( asI its convex circumference, and in its Concave to the Arazzea, with Which it is Thevariou: do form a kind of King, beipotted with Black, contiguous to the 1/17/84, in humbly conceive) by reafon the nearer obyeét is prefented to the Carma and Pupil in a greater Cone ; whereupon the Pupil iscontraé‘ted, that the Rays of the greater Cone might be the more collected, and formed in fuch aduc proportion, by the Coarétation ofthe Pupil, and thence tranf‘mitted through the tranfparent, to the more opace part of the Eye, that the more obtufc Cone of the neat object being reduced to a pomt, by the contraction of the Pupil, may make a more fenfible Appulfe upon the Rama: But the greater difiance of the other Object rendreth the Cone more acute; whereupon the Pupil necdeth no Contraétion to leflbn the Cone of the more dif'tant 0h- encornpafled as with a Girdle, and then thefe curious Proceflcs are like fo ma;ny Rays difplayed into. the Tunicle of the Retina, and Hylaoidu, which by theinterpofition oftliefe Fibrils, are lb clofely conjoyned, that they cannot be feparated without the laceration of each other. . . , So that (as I conceit/C ) one ufe of the ciliary Proceires, may be as {0 ma- :3‘:,§‘;fi,:f; ny common Bonds of the Coats of the Eye, keeping them as well as the "ml?"- Humors, from fiarting out of their proper Sphaeres, in the quick rowling motions of the Eye. _, . V .. 7 _ ,_ Another Ufe may be configned to thefe Proceiies, to be as {0 many muf- Efi‘ffldfi, cular Fibrils, gently moving the Cryltalline Humor upward and downward ""Y PW- ‘ The motion JEé'tl‘he Dilatation and Contraction of the Pupil, according to a regular courfe orthe punt. of Nature, are gentle and eafy motions; and if they be celebrated with too inward and outward, toward the greater and lets Canthm of the Eye; by, "a" reafon Objeéts prei‘ented to it, fome are near, and others more difiant, (cm: great force and quicknefs, they offer 3. Violence to the adyacent Membranes, are placed before, and others at the fide of the Eye; Whereupon the vifory which being of melt acute Senfe, are afflicted with pain in the over-hafiy mo Rays difplayed from thefe diverfly feared Objects, concurring in feveral places and points, need different refractions, that they be reprefentedto' the Quinn in due order, as Learned Dr. Higlxmore hath well obférved 5 Fibm itaque ha: Mufculorum more [a contraband/[er relaxamio Humvrcm Crzflallimtm [Mi . tion of the Pupil, as it is very evident, when we have converfed long in the dark, and are expofed ofa fuddain to a radiant Sun-(hine, which being free- ly and fuddainly darted through the enlarged Pupil, it is immediately forced by a violent Contraction, to give a {top to the immoderate incutiion to the inferumur, attollunt, an: deprimunt, dome radii ita refrangantur, ut illormit importunate Sun-beams, whence arifeth a violent pain in the Eye. concurfm‘ fit in eadem paratela, in Retina, cum illi: in oculum intidentibur. _ _ The Retina called by the Greek; flammability 5?; ti: airman", ab ampleéi- 3333:" The Pupil hath a different Magnitude,as the circumference is greater in fome, and more narrow in others. They whofe Pupil is naturally dilated fee more confufedly, by reafon the vilible obiefi is prefented througha greater Perfo- emit), a Latinit Reticularis, quad figuram rem dmuli'iflr, as being {omeWhat ""9" Km" like a Cai'ting-net in Figure, as many famous [Anatomifls will have it 5 But I beg their pardon, and conceive it more probable that this Coat was called Reticulum from thenumerous Veins and Arteries derived from the Mom, and branched up and down this Membrane in a kind of Network, and not from the fimilitude of a Pooch, by reafon upon that account, the Sclerotim and "W911 may deferve the fame name of Retiformix, as well as the Retina, in refpeét their Concave Surfaces do exceed their metfllheriml Surface, fortiewhat refembling a Cafling-Net, as well as the Retina. . . This Membrane taketh its rife from the pulpy fubflance of the Opticlc Nerve, not altogether unlike that of the Brain, which is propagated all along ration with an obtufe Cone, which maketh a faint Appulfe upon the Organ ofviiion : But they on the other fide have a more clear Sight, who are endued with a lefs Pupil, in which the Rays of Light ( enwrapping the vifible Image of things) pafling through afmall Foramen, are more colleéied and united, and ptefented in a point, and being tranfmitted through the Diaphanous parts of the Eye, at Mt make a more brisk Appulfe upon the Retina. And the Iris in fever-a] perfons hath larger or more fmall Perforations, ma- king greater or leis Circles in the Pupil of the Eye, through which a more free or {paring pmportion of Light is received into the tranfparent parts of the inward receis of the Brain, which being dilated, is the Origen of the Retina, which expandeth it {elf [0 far, as to encompals in its Sinai the vitreous Humor, and halfe the Globe of the Cryfialline, where it is united to its thin proper Membrane, Calledingmfis‘, {0 that the Retina arifing from the the Eye, whence arifeth variety of Sight; They who are endued with a di' lated Pupil, fee heft in the Night, and Shady places, and are offended in the Day with bright Rays of Light, which cutting through a great Foramen of the Iris, give diiturbance to the more tender parts of the Eye, confounding OPtiCk Nerve, and almol't encircling the vitreous Humor, is inferred into the the Sight; And they who have a narrow Pupil. are leis difcompofid in the terminations of the greater portion of the Sphazre belonging to the Crylialme Humor, giving a check to the exorbitant Flux of.- the Vitreous Humor, and containing the Cryftalline in its proper Sphere. And the Retina being day, with the bright beams of Eight, which being more fparingly entcrd rained through marrow circle of the Pupil, give orderly and fair Applillcs upon the Rating. {11: dime. The i‘ioreflm ,,,,,,,,_ The Trough: ciliare: are fo fi'yled from refembling Hairs feared in the Limlmr, or Margent of the Eye-brows. Thefe rare Procefles feem to reprefen: ('0 many Black lines, drawn by Natures fine Penfil, making as it Wm ‘ rmly conjoyned round about the Mom, is a kind ofrlnterfepim'ent, parting the Cryf'calline Humor and the Eye in the middle, and dividing them almo mtg two Hemifpheres, though I conicfs the anterior is'fomewhat 1er then the 0 trier. divers minute Shades in the tranl'parent part of the Eye There Having |