Involuntary Iridectomy

Sir,?I must plead guilty to having performed many iridectomies unintentionally, and at the same time point out the cause of this little accident in most of my cases. This was a "bellying" of the blade of the Grafe's knife. If instead of the knife being, except at the point, of equal thickness and width there be a " belly " or greater width in the forepart of the blade, leaving the part near the handle thinner or narrower, this narrow part is insufficient to completely till the opening made by the wider part; the aqueous flows out and allows the iris to come in the way of the blade. If the knife be blunt, the aqueous is more certain to escape prematurely. Some years ago when far from any instrument maker I found myself without a decently sharp knife except one with a curved cutting edge. In almost every operation I did with this knife I cut the pupillary edge of the iris.