To this purpose the Patient being set down with his Eyes turn'd toward the Light, and having his sound Eye bound up, the Surgeon must likewise sit on a higher Seat, whilst the Patient's Head is held by a Servant; and his Eye being turn'd toward his Nose, is kept steady with a Speculum Oculi, which is a little Iron-Instrument made like a Spoon, pierc'd in the middle, so that the Ball of the Eye may be let thro' this Hole: Then the Surgeon taking a Steel-Needle either round or flat, accordingly as he shall judge convenient, perforates the Conjunctive at the end of the Corneous Tunicle, on the side of the little Corner of the
Eye, and boldly thrusts his Needle into the middle of the Cataract, which he at first pusheth upward, to loosen it with the Point of the Needle; and then downward, holding it for some time with his Needle below the Apple of the Eye. If it ascend again after it is let go, it must be depress'd a second time; but the Operation is finish'd when it remains in the same place whereto it was thrust; neither is the Needle to be remov'd till this be done, and the Cataract entirely couch'd. In taking out the Needle, the Eye-Lid must be pull'd down, and press'd a little over the Eye.
The Dressing and Bandage,
Is to cause both the Patient's Eyes to be clos'd and bound up; then he must be oblig'd to keep his Bed during seven or eight Days, and some Defensative is to be laid upon the sore Eye, to hinder the Inflammation.
M. Dupré, Surgeon to the Hospital of Hôtel-Dieu at Paris, a Person well vers'd in these kinds of Operations, hath observ'd, that after the same manner as Cataracts were form'd in a very little space of time in perfect Maturity; it happen'd also very often, that the Cataracts which were suppos'd to have got up again, were not the very same with those that were couch'd, but rather a new Pellicula or little Skin, which sometimes hath its Origine in the top of the Uveous Tunicle, and is caus'd only by a very considerable Relaxation of the Excretory Vessels from the Sources of the Aqueous Humour which in filtrating permits the running
of many heterogeneous Parts, the Encrease of which produceth a new Cataract.
Of other Operations in the Eyes.
Sometimes a sort of purulent Matter is gather'd together under the Corneous Tunicle; so that to draw it out, the Eye must be fixt in a Posture with the Speculum Oculi, and after a small Incision made therein with a fine Lancet, is to be press'd a little, to let out the Matter; but if it be too thick, it may be drawn forth by sucking gently with a small Tube or Pipe, having a little Vial in the middle, into which the Matter will fall as it is suck'd out.
Sometimes a small Tumour ariseth in the Eye, which being ty'd at its Root with a Slip-Knot, to streighten it from time to time, will at length be dissolv'd: But if the Tumour lie in the Hole of the Apple of the Eye, this Operation must not be admitted, lest the Scar shou'd hinder the Passage of the Light. Sometimes also a somewhat hard Membrane, call'd Unguis, appears in the great corner of the eye, which when it sticks thereto, may be cut off by binding it; this is done with a Needle and Thread, which is pass'd thro' the Membrane, and afterward ty'd.
If the Eye-Lids are glu'd together, a crooked Needle without a Point may be threaded, and pass'd underneath 'em; then the ends of the Thread may be drawn, to lift up the Eye-Lids, and they may be separated with a Lancet.