ANATOMY OF REGIONS. 
203 
are continued without well marked separation, the superior 
with the orbital region, the inferior with the cheek and chan- 
frein. We may, however, say that their approximate boundaries 
is the sharp edge of the orbite. They are two in number, one 
superior, one inferior, united at their extremities to form the 
commissures or angles of the eye, one internal obtus the great 
or nasal angle ; one external small or temporal angle. They 
differ from each other in their external forms. The superior 
is convex from side to side, and from above below ; it lias a 
free, thin, sharp border, upon which are found implanted long, 
stiff hairs, turned outward and downward. These eye lashes are 
found on the middle of the free border; they are missing in the 
internal third and the external fifth. In the middle they are quite 
long. 
When the eye is open the free border of the eyelid de¬ 
scribes a curve in its two external thirds, and a straight line in 
the internal third—a more marked curve unite these on a line 
with the internal and two external thirds. 
The anterior surface offers two well marked fissures, parallel 
to the free border ; one is about one millimeter to one millimeter 
and one half from the border, the other about three millimeters 
higher than the other. The eyelid is separated from the eye 
brow by a deep fissure running along the superior orbital arch, 
below which it is situated. When the eyelids are closed the 
three fissures disappear, and then one has a convex, uniform sur 
face, while the curves of the free border disappear and form a 
transvenal fissure almost straight. 
Above the internal third of the eyelid one finds a flat surface, 
irregularly triangular in form, which sometimes presents the con¬ 
tinuation of the external part, but which offers oftener a flat sur¬ 
face as a consequence of the contraction of the muscular fascicu¬ 
lus which stretches the skin of that part of the region. The 
internal face is smooth and concave, to adapt itself exactly to 
the convexity of the globe of the eye. It is lined by the con 
jonctiva which, folding back over the eye, forms the superior and 
inferior oculo-palpebral fissure. u 
The inferior eye lid is belter limited ; it^uImIv convex an 
