THE EYE 



203 



postero-superior wall, which is usually much thinned, is opened very carefully 

 in the middle line, and the tumour is removed piecemeal. The lateral rela- 

 tions of the hypophysis (p. 225) are pushed aside by the growth of the tumour 

 and run little risk of injury. Lateral radiograms (Fig. 60) clearly demon- 

 strate the size of the fossa hypophyseos (sella turcica) and it is definitely 

 enlarged in these cases. 



THE EYE. 



The Eyelids. The eyelids are supported by the tarsi (tar sal 

 plates), which consist of condensed fibrous tissue, and from 



Levator palpebrse superioris 

 Superior fornix of conjunctiva ^ ^ ^ 



Ciliary process 

 nus venosus sclers 

 Posterior chamber 

 Superior tarsu 



Iris 



Cornea 



Anterior 



chamber 



Lens 



Inferior tarsu 

 Sinus venosus sclerse 



Zonula ciliaris- 

 Orbicularis oculi 



Inferior fornix of conjunctiv 



Hyaloid canal 



FIG. 61. Diagram of a Sagittal Section through the Eye. 



their margins the medial and lateral palpebral (tarsal) ligaments 

 extend to the medial and lateral borders of the bony orbit. 

 Each tarsus is separated from the skin by a muscular layer 

 and subcutaneous tissue, and the latter, being very loosely 

 arranged, is readily distended by effusions. Further, the skin 

 of the eyelid is so thin that an effusion of blood into the sub- 

 cutaneous tissue becomes apparent at once as a " black eye." 

 Numerous sebaceous glands are situated in the free margin of 

 the eyelid, and, when they become involved in suppurative 

 inflammation, they give rise to the condition known as a " stye." 

 The deep surfaces of the lids are lined by a mucous membrane, 



