Cialis Generico Farmacias Similares Mexico | OVERNIGHT Delivery!







































cured (Fig. 5) by movement of the arm (OO) in an "East and West" direction along the lateral transverse bars (F), the fragments are moved into alignment in the long diameter of the bone by oper- ating (Q). The ends of the fragments are now Cialis Generico Farmacias Similares Mexico allowed to come into end to end apposition by the reverse gear (indicated in Fig. 3), if necessary, whereupon the fragments are ready for operation. The fragments are now in perfect alignment and apposition, and the clamp holding them firmly. The superficial surface of these fragments lies exposed, unobstructed by any part of the clamp. The condi- tions are thus ideal for readily applying the bone graft or other fixation agent. (I wish to acknowledge my indebtedness to Mr. R. E. Klett of the Klett Alanufacturing Co., Inc., of New York, for his assistance and cooperation in Cialis Generico Farmacias Similares Mexico the manufacture of this instrument.) 40 E.\ST Forty-first Street. A STUDY OF IMAGES REFLECTED FROM THE CORNEA, IRIS, LENS, AND SCLER.\. By W. H. B.\tes, M. D., New York. (From the Department of Physiology of Columbia University and the New York City Aquarium.) Part I. INTRODUCTION. It is generally believed that the accommodative ])0\ver of the eye is due to a change in Cialis Generico Farmacias Similares Mexico the curvature of the lens. This view, Helmholtz says, was first advanced by Descartes (1596-1650), while the first proofs in support of the theory were presented by Young in his celebrated treatise on the Mechanism of the Eye, published in 1801. The theory attracted little attention at the time. but was'accepted later, mainly upon the authority of Helmholtz. whose investigations into the cause of accommodation were published about the middle of the last century. Helmholtz was led to this conclu- sion by what appeared to him to be changes in the size of an image, or images, reflected from Cialis Generico Farmacias Similares Mexico the front ]iart of the crystalline lens. It appeared to him that during accommodation these reflections were smaller than when the eye was Cialis Generico Farmacias Similares Mexico at rest ; and since an image reflected from a convex surface is dimin- ished in proportion to the convexity of that surface, he concluded the front of the lens must become more convex during accommodation. In the cornea he observed no change, and while he l)clieved that a change took place in the back of the lens, he considered it so slight as to be negligible. I Iclmholtz used for his experiments : first a candle so placed that it was reflected from the cornea and the two surfaces of the lens; and then two lights — May i8, •9'Sl HATliS: I MAGUS UEI-I.IICTED FROM CORNEA, IRIS, LENS. AND SCLERA. 917 or one doubled by reflection from a mirror — so placed behind a diaphragm having two rectangular openings that the rays shone through the openings upon the cornea and lens. Of the images thrown Cialis Generico Farmacias Similares Mexico upon the lens by means of the naked candle he says in his Ilandbuch der Physiologischen Optik, page 121 :' "Both these images are very much tamter than the reflection from the cornea. That from the front of the lens forms an upright image of the flame somewhat larger than that reflected from the cornea, but usually so faint that the form of the flame can- not be definitely distinguished." The results obtained Cialis Generico Farmacias Similares Mexico when :i diaphragm was used with two lights were better. Two images were then formed on each of the reflecting surfaces; and it appeared to the investigator that those on the front of the lens approached each other during accommo- dation and separated when the eye was at rest. ( See diagram, IJandbuch dcr Phxsiologischen Optik, p. I -.) " llelniholtz apjiears to have been convinced of the correctness of these observations and of the theory based upon them, and was only doubtful of the means Cialis Generico Farmacias Similares Mexico by which the supposed change was accom- l)Iishcd. His explanation of the ])henomenon of ac- commodation was soon universally accepted, and has bec-ii imivcrsally stated as a fact. Jt is the accepted belief of modern o])lithalni()logy, and has been sum- med up by De Schweinitz in his recent textbook on the eye as follows : "Inasmuch as the eyeball is inextensible, it cannot adapt itself for the perception of objects situated at different distances by increasing the length of its axis, but only by increasing the refractive power of its lens." (Diseases of the Eye, pp. 24 and 25.) There have, however, been many other theories of accommodation. Arlt ascribed the phenomenon to a lengthening of the eyeball, but later abandoned the theory out of deference to the authority of Ilelm- hollz and Cramer. In the introduction to his treatise on shortsight {Uher die Ursaclien and die linstehiDu] der Kiircsieliti(/keil) he says: "An hypoliicsis of the mechanism of accommoda- tion (movement of the posterior wall of the eye — Locomotion der liiiitereii Augemaand) which later was proven to be untenable led me to the question whether, in myopia, the eyeball, Cialis Generico Farmacias Similares Mexico as was to be ex- l^ected according to that hypothesis, might be lengthened in the direction of the sagittal axis, and in ilie course of time it was possible to ]>resent ana- tomical proof that shortsight was generally asso- ciated with such a lengthening, due to a permanent bulging (Riickdrangung) of tlie posterior wall. . . . Since the introduction of the ophthalmo- .