XLV. Dissection of the eyeball. 



/. Appliances. The eyes, already partly dissected, which 

 have been kept in an ice chest; physiological operat- 

 ing case. 



2. Dissection. a. Anterior dissection: Fix the eye to the 

 board, cornea upward, using the dissected muscles as 

 guys. 



(1) Describe the cornea as seen from the front. Does 

 the radius of curvature of the lateral meridian seem 

 to be the same as the radius of curvature of the ver- 

 tical meridian? With heavy scissors remove the cor- 

 nea, leaving a margin of one-eighth inch anterior to 

 its junction with the iris. 



Examine the cut surface of the cornea with a lens. 



(2) Through the elliptical opening thus made examine 

 the iris as to texture, etc. 



(3) Holding the margin of the cornea with strong for- 

 ceps, carefully dissect the sclerotic coat from the 

 choroid for about one eighth of an inch posterior to 

 the angle of the anterior chamber. Locate four points 

 in the margin from which incisions may be made 

 antero-posteriorly between the insertions of the recti 

 muscles. From the points located make the incisions 

 posteriorly as far as the equator of the eyeball. Dis- 

 sect each flap from the underlying choroid; remove 

 the pins which fix the recti muscles, and through 

 traction draw the flaps back; fix. 



(0) Make a drawing of the choroid with its irideal 

 and ciliary portions thus exposed. 

 195 



