| OCR Text |
Show VISION DR. A. F. RICH, member. American Optometric Assn. In optometry, present-day examination of the eyes is divided into more than 25 tests ranging from simple visual acuity measurements, for which there are no less than six different types of apparatus, up to precision measurement of corneal curvature, lens defects, accommodative amplitude, ampli-tude, muscular balance or imbalance, stereoscopic faculty, facul-ty, light sensitivity of the retina, extent of the visual fields, amount of illumination necessary for various tasks, and so forth. But let us consider the eye examination from its beginning . . . In tracing the development of examination procedure to determine the proper lenses for the individual, all glasses at first were made complete, with the lenses of the same focus for each eye. (Now we know that very rarely are the two eyes alike). A variety of lenses in different frames are available, the patient selecting the one through which he could see the best. After a while, these glasses were classified according to their focal length, for instance, a Number 13 spectacle was one which would focus fo-cus 13" from the eyes. Later, an assortment of lenses of various focal lengths was arranged in a trial case, each lens mounted in a rim of standard diameter which would be placed on the patient's face, and different trial lenses inserfed, permitting the patient to determine which was the best focus for each eye. This was the beginning of eye examinations, or refraction. refrac-tion. The next step occurred when the men who sold these glasses began to help their customers in the selection of lenses which would give them the maximum of clarity of vision, and they became known as Sight Testing Opticians. Op-ticians. Just as the blasksmiths because they had pliers and tongs and were strong were called upon to pull teeth, and the barbers were called upon to perform surgery because they had sharp knives and were experienced in blood-letting, so were the jewelers and watchmakers of the early days because of the frequent need for repairs on glasses which required their small tools, such as screwdrivers screw-drivers and pliers more frequently called upon by the public to service their glasses than any other tradesmen or craftsmen, and this resulted in the jewelers and watchmakers watch-makers taking up the work of fitting glasses as well as making and repairing them. Next week, more about the development of modern examination ex-amination techniques in optometry. |
