are fused by convergence and appear to macular perception, that is, first degree be projected in front of the plane of the fusion, can be trained), the anaglyphs stereogram (pseudoscopy) . can be used as an aid in the diagnosis of Following the explanation of stereop- suspension, hyperphoria, and cyclophoria. The idea is a fascinating one, and the sis, Dr. Dobson describes the anaglyph in detail. To summarize briefly, each pic- actual technique is extremely simple. ture of the stereoscopic pair is colored in The anaglyph can be used only where complementary red and green and super- good, bright illumination is available, for imposed so that one pair of correspond- much of the light is cut out by the ing points on the plane of the paper are bichromatic spectacles, and the desired efcoincident. All parts behind the plane of fect is almost lost in subdued illumination. In the opinion of this reviewer the the paper are seen by relative divergence, and all parts in front of this plane are greatest benefit from this device will be seen by convergence when viewed obtained in the treatment of the heterothrough a screen of complementary col- phorias, the manifest squints being someors. In other words, the pictures are over- what uncertain regardless of the type of lapped in such a fashion that when orthoptic training used; also as a periodic viewed through a bichromatic screen, home treatment for the patient whose parts of the picture are seen in apparent muscle imbalance has been corrected or crossed diplopia and other parts are seen improved by other means. Lastly, it is a in apparent homonymous diplopia. In or- compact, inexpensive, easily operated adder to fuse the crossed images, a con- dition to the orthoptist's armamentarium. W. H. Meinberg. vergence effort is required, and conversely, a divergence effort is necessary to fuse the homonymous images. The fused picture is seen in monochrome. The un- AN INTRODUCTION TO THE MATHEMATICS OF OPHTHALwanted images are rendered invisible by MIC OPTICS. By Paul Boeder, Ph.D. the screen. By constructing a series of anaglyphs Clothbound, 224 pages. Published by the the stereoscopic pairs of which were Distinguished Service Foundation of separated by known distances, Dr. Dob- Optometry, Fall River, Mass., 1937. son was able to compute the amount of Price not stated. convergence or divergence in prism diopHere is a text on elemental optics that ters required to fuse each stereoscopic deals with mathematics in such a way pair. that the text is actually good reading. The Actual training is initiated by viewing author acknowledges that the average through the bichromatic screen such a reader must review mathematics back to series of anaglyphs, the separation of the his early arithmetic. This is done in good images of each successive picture being taste and most readers will appreciate a greater or less, according to the type of substantial reconsideration of the handtraining desired. If further effect is ling of fractions. needed, prisms with bases in or out can Quickly one is led into algebra and be placed before the eyes. geometry with a final touch on trigoBesides being a means of treatment in nometry. These are all so intimately reall cases of heterophoria (but obviously lated and so clearly written the reader is only cases of strabismus having binocular sure to enjoy the restoration of distant
mathematical memories. Optical principles and applications are indicated throughout. Further, the writer's enthusiasm is imparted to the reader to such an extent that he will be led to perform some of the suggestions outlined. The greatest usefulness of the book no doubt will be to postgraduate students in ophthalmology, for it will make possible an enjoyable understanding of the subject of optics. H. Rommel Hildreth. GIZA MEMORIAL OPHTHALMIC LABORATORY, Eleventh annual report, 1936. 147 pages, illustrated. Printed by Schindler's Press, Cairo, 1937. Price 25 P. T. The Giza Memorial Ophthalmic Laboratory in Egypt is a central pathological laboratory for the Government Ophthalmic Hospitals both permanent and traveling. It standardizes the ophthalmic training of all candidates for the Government Ophthalmic Service of Egypt by giving intensive postgraduate courses which must be passed by the candidates before their appointment to the Government Eye
Service or before they are allowed to enter the private practice of ophthalmology. During the year 1936, 554 specimens were examined. Short reports are given on interesting cases, including the following: hyaline bodies in caruncle, angioma of caruncle, epidermoid carcinoma of caruncle, ossification of tarsus in trachoma, heterotopic cartilage in conjunctiva, epidermoid carcinoma of palpebral conjunctiva, sarcoma of palpebral conjunctiva, bilharzia1 granuloma of bulbar conjunctiva, epidermoid carcinoma of bulbar conjunctiva, intra-epidermal squamous-cell carcinoma of bulbar conjunctiva, sarcoma of bulbar conjunctiva, epidermoid carcinoma of limbus, metastatic cerebral tumor with choked disc, orbital giant-cell tumor of bone, and mixed-cell sarcoma of the orbit. Tuberculous lesions of the eye are rare in Egypt, but four cases were seen during 1936, including a tuberculous ulcer of the eyelid in a girl of seven years, tuberculosis of the conjunctiva in a boy aged four years, and bilateral tuberculosis of the lacrimal gland in females aged eighteen and twenty years. Lawrence G. Dunlap.