76 



Fig. 19. 

 This cut (after Schlampi)) illustrates how the double convex lens 

 is employed in illuminating the eye or parts of the eye for the pur- 

 pose of examination. The examination is made in a dark room or at 

 night ; the glass lens is moved forward and backward until the 

 candle's rays are focussed upon the desired part or various parts, as 

 it is upon the cornea and lens in the above cut. 



or window sliould be backward from tlie head and outward 

 from the slioulder or body. By employing tlie double con- 

 vex lens or concave mirror, the transparent or opaque condi- 

 tion of the cornea and the aqueous humor may be distinctly 

 observed and many opacities can thus be seen that are in- 

 visible in ordinary daylight. By employing atropine to ex- 

 pand the pupil, slight opacities of the lens may be made 

 distinct and cloudiness of the vitreous humor may be ob- 

 served. These methods of illuminating the eye also enables 

 one to carefully examine the condition of the iris. 



The opthalmoscope is an instrument that is used by occu- 

 lists to look at the retina, its bloodvessels, the papilla optical 

 and to determine the degrees of farsightedness, shortsight- 

 edness, astigmatism, etc. Its use, however, requires great 

 skill and much practice ; hence, directions for using it will 

 be omitted, since they would be of little value to the aver- 

 age man. 



In preparing this bulletin, the writer has made frequent 

 and extended references to the following books, pamphlets, 

 and medical journals : 



Mueller' s^ — ' ' Augenheilkunde. 

 Schlampp's — "Augenuntersuchungen." 



EUenberger-Shiitz — "Jahresbericht iiber Veterinar Medicin. 

 Jahr 1891." 



