Because the sulci demarcate the junction between loose loose palpebral and dense cheek tissue.any edema ,adipose herniation is limited upto that sulci.
Each eye lid is divided by a horizontal furrow into orbital and tarsal part. Lines of minimal tension: Formed by 2 groups. First is due to habitual expression Second is due to relaxarion of palpebral skin itself. Usually all incisions are taken parallel to these lines except in repair of ectropion where orthogonally incisins are made.
In caucasians with lids open,lateral canthus is about 2mm above the medial thus imparting inferomedial shape to fissure In mongoloids obliquity is increasd with a dermal fold over medial canthal regions called epicanthal fold which can over lap the caruncle.
Striated part is palpebral part of orbiclaris palpebrum
Temporal and zygomatic branches of facial nerve.
Medial horn passes over the reflected tendon of superior oblique and fuses with medial canthal tendon Lateral horn divides lacrimal gland into orbital and palpebral part and inserts into superior edge of lateral canthal tendon
Extremities of tarsal plates:The lateral ends of tarsi are attached to whitnalls ligament and medial ends by palpebral ligament to anterior lacrimal crest ,frontal process of maxilla
Anterior part: it fans out laterally at the ant lacrimal crest Gives origin to superficial portion of orbicularis muscle Angular veins,artery pass over medial part of ant part. Continues laterally at medial canthus splits into upper and lower bandsattached to upper and lower tarsal plates resembling Y alphabet Posterior part: passes behind the lacrimal sac from ant lacrimal crest to post lacrimal crest
Arranged in a single row vertically parallel to each other.20-30 in a lid. Structure: central duct,runs straight perpendicular to lid margin,10-15 acini open from sides into central duct. Opening of meibomian glands are arranged in a single roebetween grey line and post border of lid.
Structure : single cul-de-sac.2-3 lobules.cuboidal cells line acini.
Veins are larger, numerous than arteries.2 sets of venous plexus seen
Formed by reduplication of surface ectoderm
above and below the cornea during second
month of gestation.
The folds enlarge and their margins meet and
fuse with each other
The lids cut off a space called conjunctival
The folds thus formed contain some
mesoderm for development of muscles of lid
and tarsal plates.
Lids seperate after 7th
month of intrauterine
2) Lid folds
3) Position of eyelids
5) Eyelid Margins
7) Palpebral aperture or fissure
From eyebrow downward to end in a free margin
Superior boundary of palpebral fissure
Merge into skin of cheek, where nasojugal,malar sulci
Superior lid fold
Orbital & tarsal portion
Formed by fibrous slips, from tendon of
Inferior lid fold
On skin of lower eyelids
Fibrous slips from fascia of inferior rectus
Position of eyelids
In primary position of gaze
Upper eyelid covers 1/6th
Lower eyelid just touches the cornea
the two eyelids are separated by lacus
lacrimalis, in the centre of which is a small
the caruncula lacrimalis.it is a small area of
tissue derieved from skin,contains large
modified sweat glands and sebaceous glands.
A semilunar fold called plica semilunaris lies on
lateral side of caruncle.Represnts the third eye
lid of other vertebrae.
Lid margin vascularity increases with
age,particularly in women.
When lids close eyelashes do not interlace
Upper lid : 100-150
Lower lid : 50-75
20 – 120 microns
Taper & end in fine point
Lifespan 5 months.
Replacement is fully grown in 10 wks.
Darker than other hairs and remain so except in alopecia areata.
Glands of Zeis & Moll- empty into infundibulum of each piliary gland
Cilia have no erector muscles set
obliquely,anterior to palpebral muscle reach
the tarsal plate, have a sensory innervation.
Elliptical space b/w upper & lower lid
Horizontally– 18 to 21 mm
Vertically -- 8mm
28 to 3o mm (hor)
9 to 11 mm (ver)
From without inwards, each lid has following layers:
2) Layer of subcutaneous areolar tissue
3) Layer of striated muscles(orbicularis
4) Sub muscular areolar tissue
5) Fibrous layer and tarsal plate.
6) Septum orbitale
7) Layer of non-striated muscle fibres
Elastic , fine texture, thinnest in the
The skin of medial part of eye lid differs from
temporal .more oily,few rudimentary
hairs,sebaceous glands,plentiful unicellular
sebaceous glands in basal epidermis.
From anterior part of the medial palpebral
ligament & adjacent bones
Cover orbital margins , large ellipse , meet at
lateral palpebral raphe
Intermingle with frontalis
Palpebral part of
Deep head & superficial head
From lacrimal fascia, posterior lacrimal
Pass superiorly & inf. In front of orbital
Unite at lateral palpebral raphe
From lacrimal fascia & post. Lacrimal crest
From medial palpebral ligament
Overlying upper & lower tarsus
Join laterally to form lateral canthal tendon
It is inserted over lateral orbital tubercle of
Pars lacrimalis (Horner’s muscle)
Pars ciliaris (muscle of Riolan)
Function of orbicularis
Forced closure of eyelids
Thus pull eyebrows downwards
Helps in gentle closure during blinking, sleep, soft
Entire muscle supplied by branches of 7th
Origin of LPS
At apex of orbit from the Under surface of
lesser wing of sphenoid above Annulus of
Zinn by a Short tendon whuch is Blended
with origin of SR
Course & attachments
Ribbon like belly
Axis slightly nasal
Medial & lateral horns
Aponeurosis passes through septum orbitale
LPS inserted – pretarsal skin of lid forming the
Thickened posterior part- ant tarsal surface
Few fibrous slips from post.LPS insert into
Sup. Transverse lig. Of
Thickened band of orbital fascia
extending From trochlear pulley to the
capsule of orbital lobe of lacrimal
Formed by condensation of superior
sheath of levator muscle joined
medially by the sheath of reflected
tendon of superior oblique muscle
Severing of this ligament during ptosis
surgery can lead to failure of levator function.
Nerve supply & action of
LPS Branch of superior division of 3rd
Acts as Elevator of upper lid.
tissue Layer of loose connective tissue
b/w orbicularis muscle & fibrous layer
Nerves & vessels lie in this layer
Splits lid into anterior & posterior lamina
Superiorly communicates with
subaponeurotic layer of scalp
Lower lid – submuscular tissue is a single space
Upper lid- levator muscle- divides into 2 spaces
› Pretarsal space- has peripheral arcade
› Bounded anteriorly by levator
tendon,orbicularis,posteriorly by tarsal plate,palpebral
› Limited by origin of this muscle from levator,below by
attachment of levator to tarsal plate.
› Preseptal space- triangular, bounded in front by
Orbicularis, behind by septum orbitale
Framework of the lids
Central thick part- tarsal plate
Peripheral thin part- septum orbitale/
Dense fibrous tissue, skeleton of lids
Extend from a point 7mm from lateral orbital
tubercle to lacrimal puncta,9mm from anterior
29mm long, 1mm thick
Superior tarsus is transversely cresentric
Inferior tarsus is oblong.
Surfaces: anterior and posterior
Tarsal glands embedded in substance of tarsal
i. Origin: as capsulopalpebral head from
delicate attachments to inferior rectus
ii. Extends anteriorly and splits into two and
surrounds the inferior oblique muscle
iii. Again rejoins to form the Lockwood’s
ligament and fascial tissue anterior to this
forms the capsule palpebral fascia
iv. Insertion: on the inferior fornix along
with inferior tarsal muscle and on inferior
border of tarsus
orbitale(palpebral fascia) Thin , floating membrane of
Takes part in all movements of lids
Thick & strong on lateral side,in
upper lid than lower lid.
Peripherally attached to orbital margins
called arcus marginale formed by periorbita
when it continues with periosteum of facial
Centrally it becomes continuous with tarsal
plates except where pierced by fibres of
levator in upper lid.
Weak areas in septum orbitale determines
the site of herniation of fat(orbital)
• In contact with orbital fat which seperates it
from larimal gland ,levator,tendon of sup
• Medially contact with orbital fat between
trochlea,medial palpebral ligament.
• Contact with orbital fat,expansions of inf and
Structures piercing orbital
septum Lacrimal vessels & nerves
Supraorbital vessels & nerves
Supratrochlear artery & nerve
Anastomosing vein b/w angular & ophthalmic
Superior & inferior palpebral arteries
Aponeurosis of levator muscle in upperlid
Expansion of inferior rectus in lower lid
Triangular band of connective tissue
Attached to frontal process of maxilla
From ant. Lacrimal crest
To suture line of frontal process with nasal
Divided into 2 parts
› Ant. part of MPL
› Post. part of MPL
Lateral- whitnall’s tubercle
Medially attached to lateral ends of
upper,lower tarsal plates.
Anterior surface- related to lat.palpebral
Posterior surface- check ligament of LR
Upper border- aponeurosis of levator muscle
Lower border- IO ,IR
6. Layer of non striated
Consists of smooth muscle fibres of muller,
which lie deep to septum orbitale.
Origin: arise from the inferior terminal
striated fibres in upper lid,from expansion of
inf rectus in lower lid.
Supplied by sympathetic nerve fibres.
So sympathetic irritation leads to retraction
of lids, paralysis leads to horners syndrome.
It is the posterior most layer of eyelidwhich
extends from m ucocutaneous junction at lid
margin to conjunctival fornix.
It is firmly adherent to posterior surface of
tarsal plate,mullers muscle.
Acessory lacrimal glands of
Microscopic accessory lacrimal glands
present along upper border of superior tarsus,
along lower tarsus inferior border.
2-5 in upper lid
2-3 in lower lid
Mainly by medial &
lateral palpebral arteries
Marginal Arterial arcades
Medial palpebral + lateral
Superior or peripheral
Superior branches of medial
Superficial temporal artery
Transverse facial artery
Supply Muller’s muscle
Vessels & glands of skin
Arrangement of Nerves
Submuscular plane.so to anesthetise lid,inj is given
in this compartment
From here branches pass Forward for orbicularis &
Backward to tarsal structures & conjunctiva
Voluntary blinking and winking
Upper lid elevators
Lower lid retractors
Upper lid elevators
Levator palpebrae superioris (the
primary elevator of the upper eyelid).
The superior palpebral muscle of Muller’s
Frontalis (acting as accessory elevator).
Frontalis and Muller’s muscles become important
when the levator is defective.
Muscle Attachment Nerve supply
(main upper lid
Lesser wing of the
sphenoid to the
Superior division of
nerve (also supplies
(minor upper lid
Aponeurosis of the
levator to the upper
border of the tarsal
Frontalis Scalp to the upper
part of the
Eyelid excursion during opening
In adults the upper eyelid is raised
some 10-15 mm from extreme
downward gaze to extreme upward
Tone of levator muscle:
In upward gaze, tone increases in both
the superior rectus muscle and the
levator, resulting in elevation of the
visual axis and concomitant elevation
and retraction of the upper lid.
Lower lid retractors
NO true counterpart of the levator is
present, and therefore, the opening
movement depends upon several
1. Traction exerted by the attachment of
the inferior rectus to the inferior tarsus.
2. Inferior palpebral muscle (identical to
Muller’s muscle in the upper lid).
Dynamics of opening movement
Opening of the upper eyelid takes place
Opening movements of the homolateral
upper and lower eyelids begin in phase,
although the opening movement of the
lower lid is much slower than that of the
upper eyelid due to lack of any direct
During opening movement the upper
lid moves vertically upwards, while
the lower lid moves laterally in a
Bilateral coordination and their basis:
Opening movements of the eyelids are bilateral,
symmetrical, and identical in direction and
amplitude, although they may be voluntarily
inhibited on either side.
So, the levator muscles of the two upper eyelids
behave as yoke muscles in that they act as a
team or pair, and like extraocular muscles, obey
Hering’s law of equal innervation.
This implies that the innervational
energy reaching the one levator muscle
is equal to that reaching the other.
When the levator on one side is weak, as
in unilateral myasthenia gravis or
unilateral congenital ptosis, the lid on
the unaffected side may be retracted in
an unconscious effort (based on Hering’s
law of equal innervation) to elevate the
Reciprocal innervation pattern
It exists between the levator muscle
and the orbicularis oculi muscle, i.e.
when levator receives maximum
innervation during opening the
orbicularis receives minimum
innervation and vice versa. Thus, these
muscles follow the Sherrington’s law of
Orbicularis oculi controls lid closure and is
supplied by the facial nerve.
It is divided into three main parts:
Part Position Function
Pretarsal fibers In front of the
* Respond in spontaneous blinking
and tactile corneal reflex.
* Close lid and pull lacrimal puncta
Preseptal fibers In front of the
Respond to voluntary blinking and
* Pull lacrimal fascia laterally and
create a relative vacuum in lacrimal
sac-improve tear drainage.
Orbital fibers Surrounds the
* Respond in forceful lid closure.
Blinking can be divided into
voluntary and involuntary
The involuntary blinks are
further subdivided into
spontaneous and reflex
It is a common form of blinking that occurs
without any obvious external stimulus or
voluntary willed efforts.
Spontaneous blinking does not occur or is very
infrequent during the first few months of life; yet
the delicate infant cornea does not suffer from
Average rate: 15 times per minute (12-20).
The blink rate is increased in:
1. Extremely dry conditions.
2. Strong air currents.
3. Certain emotional stress situations (surprise, anger,
A decreased blink rate occurs during times of visual
Duration: 0.3-0.4 second.
Present in the blind, hence no retinal
stimulation is required.
No discontinuity of visual sensation during
The upper lid begins to close with no lower lid
It is followed by a zipper-like movement from
the lateral canthus towards the medial canthus.
This helps the displacement of the tear film to
the lacrimal puncta which are located on the
medial side of the lids.
The exact stimulus for spontaneous
blinking is unknown.
Spontaneous blinks occurring
without gaze shifts are triggered by
a timing mechanism probably
located in the brainstem.
During each blink, the upper eyelid
covers the center of the pupil for a
period of 0.10 sec.
Due to contraction of the preseptal
fibers, as the upper eyelid reaches the
limit of its downward excursion,
electrical activity in the orbicularis
ceases and concomitantly activity
reappears in the levator.
reflexly in a response to a
Different stimuli induce a different
Examples Afferent Efferent Central
Tactile Corneal touch CNV CNVII Cortical
Bright light CNII CNVII Subcortical
Sudden presence of
CNII CNVII Cortical
Auditory Loud noise CNVIII CNVII Subcortical
Orbicularis Stretching of
CNV CNVII Cortical
Voluntary blinking and winking
is a willed coordinated closure and
opening movement of the eyelids in
The voluntary blink is under the control
of the individual (rate and degree of
closure and opening).
It is produced as a protective gesture.
Winking is unilateral voluntary lid closure.
Part of facial expression.
It is a learned activity.
Occasionally, a subject may learn to wink with
one eye but not with the other.
Minimum periods between winks are 0.3 sec.
Both are voluntary blinking and winking are
produced by simultaneous contraction of
palpebral and orbital portions of the
It is a highly coordinated reflex
between the facial and oculomotor
nuclei, whereby on closure of the
eyelids, the eyeball is rotated
upward and outward.
This is a protective mechanism
On closure of the eyelids, all the electrical
activities in the levator cease and concomitantly
the activity abruptly rises in the superior rectus
muscle and is inhibited in the inferior rectus
Bell’s phenomenon is NOT present in 10% of
otherwise healthy persons, and therefore its
absence is not necessarily a sign of disease.
Coloboma: characterised by full thckness
triangular gap in tissues of lids.
Involves nasal side.more common in upper
Cryptophthalmos:lids fail to develop and skin
passes continuously over the eye balls.
Microblepharon: abnormally small eye
lids.associated with microphthalmos or
Ablepharon: ocasionally lids may be virtually
• Acute suppurative inflammation of gland of
zeiss or moll.
Chalazion : tarsal or meibomian cyst.chronic
non infective granulomatous inflammation of
Internal hordeolum: suppurative inflamation
of meibomian gland asso with blockage of
Molluscum contagiosum: viral infection of lids
caused by a pox virus.
Waxy,umbilicated,multiple swellings scattred
over skin near lid margin
Anamolies in position of
lashes and margin
Trichiasis : inward misdirection of cilia with
normal position of lid margin.
The inward turning of lid margin and lashes is
called pseudo trichiasis.
Entropion :inturning of lid margin.
Ectropion : out rolling or outward turning of
Condition in which lids become adherent with
the eye ball as a result of adhesions between
palpebral and bulbar tissue.
Refers to adhesions between margins of
upper and lower lids.
Congenital or acquired.
Complete or incomplete.
The extent of palpebral fissure is decreased.it
appears contracted at outer canthus.
condition characterised by inability to close
the eye lids voluntarily.
Abnormal drooping of upper eye lid.
If more than 16 th of cornea is covered i.e.
1. Simple congenital
2. Asso with weakness of superior rectus
3. Part of blepharophimosis syndrome
4. Congenital synkinetic ptosis.