The American encyclopedia and dictionary of ophthalmology Edited by Casey AWood, assisted by a large staff of collaborators . at the outer canthus a delicate fold of skin called the outercommisure, which connects the upper with the lower lid. ANATOMY (GROSS) OF THE HUMAN EYE 345 The inner canthus presents an outline somewhat similar to ahorseshoe, at the free ends of which are situated the puncta lachry-raalia; these are directed a little backward, and are closely appliedto the eyeball. Here, also, is found a small, pink body—the lachry-mal caruncle—which is set down in the concavity of the ho
The American encyclopedia and dictionary of ophthalmology Edited by Casey AWood, assisted by a large staff of collaborators . at the outer canthus a delicate fold of skin called the outercommisure, which connects the upper with the lower lid. ANATOMY (GROSS) OF THE HUMAN EYE 345 The inner canthus presents an outline somewhat similar to ahorseshoe, at the free ends of which are situated the puncta lachry-raalia; these are directed a little backward, and are closely appliedto the eyeball. Here, also, is found a small, pink body—the lachry-mal caruncle—which is set down in the concavity of the horse-shoe against the eyeball; it is composed of skin and conjunctiva. The width of the lid-fissure varies greatly in different , when looking directly forward, the upper portion of thecornea is covered for about mm. by the upper lid, while the lowerportion remains exposed. The narrow, free margins of the lidsare closely in apposition when the lids are closed. An oily secretionfrom the Meibomian glands prevents an overflow of tears, exceptwhen they are formed greatly in excess of the normal. a. Muscles of Eight Eyelids (from behind).a. Corrugator muscle; b. Upper border of superior tarsus (dotted line) ; e. Lat-eral palpebral raphe; d. Lower border of inferior tarsus (dotted line); e. Cavityof nose; f. Ethmoidal cells; g. Lachrymal portion of the orbicularis muscle;h. Frontal sinus. The cilia, or eyelashes, which project in two or three rows fromthe margin of the upper lid, curving slightly upward, are larger,longer, and more numerous than those of the lower lid, which arisefrom its anterior margin and grow downward and forward. Inboth lids they are longest in the middle; toward the nasal side theyreach only to the recess in which the caruncle is placed. The chief muscle of the lids is the arhicularis palpehrarum, a pow-erful voluntary sphincter, consisting of an orbital, a palpebral, anda lachrymal portion. It is a thin, flat muscle which lies immedia
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectophthalmology, bookye
