Dr. Waqas Nawaz PMAS arid agriculture university rawalpindi pakistan

2. Eye:
 The eye or organ of vision (Organon visus) in the
broader sense of the term comprises;
 The eyeball or globe of the eye (Bulbus oculi)
 The optic nerve
 Certain accessory organs associated there with
 The accessory organs (Organa oculi accessoria) are;
 Orbital fascise and muscles
 The eyelids and conjunctiva, and
 Upper eyelid the lacrimal apparatus

3. Connection with skull:
 The bony walls of the orbit have been described in
connection with the skull; the peri-orbita, a fibrous
membrane which encloses the eyeball together with
its muscles, vessels, and nerves may be appropriately
included in the account of the fasciae

4. Eyelids or Conjunctiva:
 The eyelids, upper and lower (Pal-pebra superior and
inferior respectively), are movable folds of integument
situated in front of the eyeball.
 The upper lid more movable than the lower one, and
its free interval between the lids is termed the
palpebral fissure (Rima pal-pebrarum).
 The ends of the fissure are the
angles or canthi, and are
distinguished as medial or nasal,
and lateral or temporal
(Angiilus oculi medialis, lateralis)

5. Cont...
 The third eyelid (Palpebra tertia) is situated at the
medial angle of the eye.
 It consists of a semi-lunar fold of the conjunctiva,
known as the membrana nictitans,
 which covers and partly encloses a curved plate of
hyaline cartilage. Its marginal part is thin and usually
more or less pigmented.
 The part of it which lies in the membrane is wide and
thin.
 The deep part is narrower and thicker and is
embedded in fat at the inner side of the
 eyeball

6. Cont...
 The skin of the eyelids is thin and freely movable,
except near the free edge, where it is more firmly
attached.
 The underlying subcutaneous tissue is destitute of fat.
 The muscular layer consists chiefly of the elliptical
bundles of the orbicularis oculi, with which are
associated fibers of the corrugat
or supercilii in the upper lid and
the malaris in the lower lid.

7. Cont...
At the medial side
there is a fibrous band,
the palpebral ligament,
 which is attached to
the lacrimal tubercle
and furnishes origin to
some fibers of the
orbicularis.

8. Cont...
 At the medial commissure a bundle detached from the
orbicularis passes inward behind the lacrimal sac, and
is known as the pars lacrimalis (Horner's muscle)
 At the lateral side the fibrous layer is thicker and
denser along the free edge of the lid, forming here the
tarsus.
 The tarsus furnishes insertion to a layer of unstriped
muscle known as the tarsal muscle.
 The tarsal glands (Glandulse tarsales) are partly
embedded in the deep face of the tarsus.

9. Cont...
 The conjunctiva is the mucous membrane which lines
the lids as palpebral conjunctiva (C. palpebrarum),
and is reflected upon the anterior part of the eyeball as
bulbar conjunctiva (C. bulbi); the line of reflection is
termed the fornix conjunctiva.

10. Lacrimal Carimcle:
 there is a rounded pigmented prominence known as
the lacrimal carimcle (Caruncula lacrimalis)
 about the size of a small pea, and is covered modified
skin, connected with that of the medial commissure,
from which project a number of hairs provided with
sebaceous glands.
 slit-like opening, the pimctum lacrimal, which is the
entrance to the lacrimal duct.

11. Lacrimal Apparatus:
Lacrimal Gland (Glandula lacrimalis)
 Which secretes lacrimal fluid
Excretory ducts of gland (Ductuli excretorii)
 The pimcta lacrimalia are the entrances to the two
lacrimal ducts.
Lacrimal ducts(Ductus lacrimales)
Canaliculi
Lacrimal sac (Saccus lacrimalis)
Naso-lacrimal duct (Ductus nasolacrimalis)
 Which receive fluid & convey it to nostrils

12. Cilia or Eyelashes:
 The anterior margin (Limbus palpebralis anterior) bears
stiff hairs termed the cilia (eyelashes).
 On the upper lid the cilia are long and numerous except
at its medial third, where they are very small or absent.
 On the lower lid the cilia are often scarcely distinguish-
able from the ordinary hairs
Cilia

13. Vessels & Nerves:
Sensory Nerves
branches of the ophthalmic and maxillary
divisions of the trigeminus.
Motor Nerves
Orbicularis oculi, corrugat or supercilii, and malaris
come from the facial nerve; the levator palpebrse
superioris is innervated by the oculomotor nerve and
the unstriped muscle of the lids by the sympathetic.

14. The Orbital Fascia & Ocular Muscles
The straight muscles of the eyeball and the oblique
muscles in part are enclosed in fibrous sheaths (Fasciae
musculares)
Superficial fascia (Thin)
Deep fascia (corneo-scleral junction)
Fascia bulbi (cover the posterior part of eyeball)
Levator palpebrae superioris (thin band, above the
rectus dorsalis.
Muscles of the eyeball (Mm. oculi) seven in number—
four straight, two oblique, and a retractor
Straight muscles (Mm. recti)

15. Cont...
Retractor oculi (Surround the optic nerve)
Obliquus dorsalis s. Superior (longest and narrowest of
the ocular muscles)
Obliquus ventralis s. Inferior (wide and much shorter
than the recti)
NERVE SUPPLY
 The oculomotor nerve supplies the foregoing muscles,
with the exception of the rectus lateralis and obliquus
dorsalis, which are innervated by the abducens and
trochlearis respectively.

16. Straight Muscles (Mm. Recti):
Rectus dorsalis
s. superior
Rectus ventralis
s. inferior
Rectus medialis
Rectus lateralis
 They are all band-like
 arise close together around the optic foramen
 diverge as they pass forward to the eyeball.

17. The Eyeball (Bulbus oculi):
situated in the anterior part of the orbital cavity
protected in front by the eyelids and conjunctiva, and
in its middle by the complete orbital ring
related behind to the fascia bulbi, fat, and ocular
muscles.
form approximately of an
oblate spheroid,
composed of the segments of
two spheres of different sizes

18. Cornea:
forms the anterior fifth of the fibrous tunic
transparent
colorless
non-vascular
oval in outline
anterior surface (Facies anterior) is convex
central part is termed the vertex comeae.
posterior surface (Facies posterior) is concave
The margin (Limbus corneae) joins the sclera
cornea is thinnest at the vertex

21. Cont...
Cornea consists of;
Epithelium corneae
Lamina limitans anterior
Substantia propria
Lamina elastica posterior
Endothelium camerae anterioris
Nerves (derived from the ciliary nerves)

22. The Retina:
The retina or nervous tunic of the eyeball is a delicate
membrane which extends from the entrance of the
optic nerve to the margin of the pupil.
consists of three parts
 large posterior part
• pars ciliaris retinae
• Pars iridica retinae
• optic papilla
(Papilla nervi optici)
 area centralis retinae

23. Cont...
 pigmented epithelium (Stratum pigmenti retinae)
arteria centralis retinae
anastomotic branches from the short ciliary arteries
veins accompany the arteries except in the capillary
plexuses; their walls consist merely of a layer of
endothelial cells, around which are a lymph-channel
and sheath.

24. Chambers Of The Eye:
anterior chamber (Camera oculi anterior)
posterior chamber (Camera oculi posterior)
The chambers are filled by the aqueous humor
(Humor aqueus)
clear fluid which consists of about 98% of water, with
a little sodium chlorid and traces of albumin and
extractives.
It is carried off chiefly through the spaces in the
zonula ciliaris (suspensory ligament of the lens) into
the plexus venosus sclerae.

26. Refractive Media Of The Eyeball:
vitreous body (Corpus vitreum) is a semifluid
 transparent substance situated between the crystalline
lens and the retina
 In front it presents a deep cavity, the fossa hyaloidea,
which fits the posterior surface of the lens
vitreous stroma (Stroma vitreum)
vitreous humor (Humor vitreus)
The surface is covered by a condensation of the stroma
known as the hyaloid membrane (Membrana
hyaloidea)

27. Cont...
crystalline lens (Lens crystallina) is a biconvex
Equator of the lens (Equator lentis), is almost circular
Anterior surface (Facies anterior) is convex
Posterior surface (Facies posterior) is much more
strongly curved than the anterior
The central points of the surfaces are the anterior and
posterior poles (Polus anterior et posterior lentis), and
the line which connects them is the axis of the lens
(Axis lentis).
zonula ciliaris is suspensory ligament of the lens

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