A Maddox rod found in any complete trial case may be placed before one eye. Have the patient fix on a candle flame, say twenty feet away. The flame appears drawn out into a luminous line. This line can not be fused with the candle flame as the other eye sees it if there is heterophoria. The amount and kind of disturbance is somewhat indicated by the distance and direction of the luminous line and the flame. The exact amount can be measured by the use of a prism that will cause them to fuse. Next the patient should be taken to the dark room and a careful inspection of the anterior segment of the eye should be made with oblique illumination. First use the unaided eye, then use a lens that magnifies. The 20 D plus lens from your trial case will suffice for the magnification. Note the transparency or lack of it in the cornea and crystalline lens; the depth of the anterior chamber and the appearance of the pupil and iris. Now we are ready for the ophthalmoscopic examination. =The Ophthalmoscope.=—This is an instrument that commands great respect. Any one who is interested in eye troubles must have and use the ophthalmoscope if he expects to be efficient in diagnosis, upon which, of course, intelligent treatment must forever depend. One must try and try again in order to become proficient in the use of the ophthalmoscope. A Schematic Eye is of great assistance to a beginner who does not have clinics or patients on whom to practice. Such an eye with full directions can be obtained at almost any optical goods store. It will make the study of ophthalmoscopy easy and interesting. The pupil can be regulated to any size and the eye can be made short (hyperopic), long (myopic) or normal (emmetropic) for study. The efficient use of the ophthalmoscope makes the diagnosis of internal diseases of the eye as easy as the diagnosis of external diseases of the eye. Only some rare conditions will puzzle, and that is true of any part of the anatomy. The ophthalmoscope is a simple instrument; its chief function is to illuminate the interior of the eye. The value of ophthalmoscopic findings depends on their correct interpretation by the examiner. The ophthalmoscope has a mirror to reflect the light into the eye. It has two discs on which are mounted convex (plus) and concave (minus) lenses. The larger disc has seven plus and eight minus lenses. To these may be added the lenses in the smaller disc making many combinations. A drop of a 2% solution of cocaine or homatropine may be used as a mydriatic where one can not otherwise see clearly the fundus. If no mydriatic is used a somewhat weak illumination should be employed in order not to arouse the accommodation to much activity and make the pupil small. If there is any opacity in the media a strong illumination should be used. The room should be dark; the darker the better.