2. Introduction to the Eyelids
• An eyelid is a thin fold of skin that covers and
protects an eye.
• Protects against the dust, injury and excessive
light by its closure.
• It spread the tears on the eye surface to keep it
moist, since the cornea must be continuously
moist.
• Also involve into exit of tears into drainage
system at medial canthus.
• They keep the eyes lubricated when asleep.
4. GROSS ANATOMY
• Each eyelid is divided by a horizontal furrow
(sulcus) into an orbital and tarsal part.
• uper sulcus formed by the aponneurotic fibers
of levator muscle into the skin.
• Lower sulcus is due to connection of
orbicularis muscle
with skin.
5.
6. Position of eyelid
– When eye is open, the upper lid covers
about 1/6th of the cornea & the lower lid
just touches the limbus.
– When eye closed, it covers the whole
cornea
7. Palbebral fissure or aperture
• There is the elliptical space b/w the upper and
the lower lid called Palbebral fissure.
• When the eyes are opened, it measures about
10-11mm vertically in the centre and about
28-30mm horizontally.
8. Canthi or angles of eyelids
• The two lids meet each other at medial and
lateral angles(or outer & inner canthi).
• Lateral canthus is directly in contact with the
eye ball
• Medial angle is rounded and 5mm medial to
the eye ball.
• The medial canthus is about 2mm higher than
the lateral canthus.
9. Medial canthus
• Medially eyelids are separated by a small
triangular space called lacus lacrimalis.
• In the centre there is pinkish elevation called
caruncula lacrimalis.
• On the lateral side of the caruncula there is
semilunar skin fold called plica semilunaris
10.
11. THE LID MARGIN
• It is About 2mm broad and is divided into two
parts by punctum.
• The medial 1/6th, the lacrimal portion is
rounded and devoid of lashes or glands.
• The lateral 5/6th of eyelid margin is the ciliary
portion consist of rounded anterior border, a
sharp posterior border and an inter-marginal
strip.
12. Conti…
• 5mm from the medial angle there is small
elevation called papilla lacrimalis
• On the papilla there is small hole called
punctum lacrimalis.
• Punctum varies from 0.4 to 0.8mm in size
• It is the part of lacrimal apparatus for the
drainage of the tears.
13. Eye lashes
• Short curved hairs are present on the margins of
the eye lids from the lateral angle of the eye to
the papilla.
• More numerous in upper lid and curved upward
• And those of lower lid curved downward.
• In front of the posterier edge of the margin of the
lids there are the openings of the tarsal gland
seen as yellowish line on the inner surface of the
everted eye lid.
