The student's guide to diseases of the eye . Fig. 34.—Ophthalmoscopic ap-pearance of healthy disc, asseen in the erect image. Darkvessels, veins. Physiologicalpit stippled. x 15 diameters(after Jaeger).. Fig. 35.—Vertical section of healthy optic disc, &c. x about Retina, outer layers shaded vertically, nerve-fibre layershaded longitudinally. Ch. Choroid. Scl. Cr. Lamina cribrosa. Subvaginal space betweenouter and inner sheath of optic nerve. The central veinand one of the divisions of the central artery are seen inthe nerve and disc. OPHTHALMOSCOPIC EXAMINATION 5 If th
The student's guide to diseases of the eye . Fig. 34.—Ophthalmoscopic ap-pearance of healthy disc, asseen in the erect image. Darkvessels, veins. Physiologicalpit stippled. x 15 diameters(after Jaeger).. Fig. 35.—Vertical section of healthy optic disc, &c. x about Retina, outer layers shaded vertically, nerve-fibre layershaded longitudinally. Ch. Choroid. Scl. Cr. Lamina cribrosa. Subvaginal space betweenouter and inner sheath of optic nerve. The central veinand one of the divisions of the central artery are seen inthe nerve and disc. OPHTHALMOSCOPIC EXAMINATION 5 If the refraction be E. or H. no lens is neededbehind the mirror; if M., a concave lens must beplaced in the clip behind the mirror, of sufficientstrength to give a good, clear, erect image. Theobserver must come as near as possible to thepatient. By reference to Fig. 33 it will be seen that onlythose rays are useful which strike near the centre ofthe mirror, none others entering the patients pupil;hence, if the aperture in the mirror be too large thefundus will not be well lighted. It should not belarger than 3 mm., nor smaller than 2 mm. Keratoscopy, Retinoscopy, or Pupilloscopy. In this metho
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Keywords: ., bookcentury1800, booksu, booksubjecteye, booksubjectophthalmology
