The eyeball contains three layers - the outer fibrous tunic, middle vascular tunic, and inner nervous tunic. The fibrous tunic includes the sclera and transparent cornea. The middle vascular tunic (uvea) contains the choroid, ciliary body, and iris. The inner nervous tunic is the retina. Accessory structures include the eyelids, lacrimal apparatus, conjunctiva, and extraocular muscles. The interior of the eyeball is divided into the anterior and posterior chambers by the lens, filled with aqueous humor and vitreous humor respectively.

1. Eye

2. Introduction
• Eyebal is the organ of
site
• Loaction- occupies the
anterior 1/3rd of orbital
cavity.

3. Anatomy of
the eyeball
Accessory
structures
Structures of
the eyeball
Interior
of the
eyeball

4. Accessory Structures
• Eye lids
• Eye Lash
• Eye brows
• Lacrimal apparatus
• Conjunctiva
• Tear film
• Extra ocular muscles

5. Eye Lids
• It’s a movable thin skin
folds covering the eyes
• Plays a role in the
protection of the eye from
injury by rapid closure.
• The eye lids include the
tarsal glands that secretes
oily material for
lubrication and prevents
evaporation of tears and
stabilize the tear film.

6. Eye Lash & Eye brows
• The eye lashes and eye
brows provide extra
protection for the eye by
preventing the entrance
of microbial agents and
dust and other matter
that can cause harm to
the eye.

7. Lacrimal Apparatus
• The Lacrimal
apparatus is made up
of many structures
that is involved in
nutrition ,
• Protection against
pathogens and
hydration roles.
• The Lacrimal gland
is located superior to
the eye lids and is an
exocrine gland

8. • The Lacrimal ducts dump the tears on the surface
of the conjunctiva coming from the Lacrimal
gland directly and they range from 6 to 12 duct.
• The Lacrimal puncta are 2 opening that collects
the tears from conjunctiva and drains them to
Lacrimal canal.
• The Lacrimal canal starts at the Lacrimal
punctum and ends at the Lacrimal sac , it delivers
the tearsto the Lacrimal sac.
• The nasolacrimal duct descends from the
Lacrimal sac to open at the meatus in the nose

10. Conjunctiva
• Conjunctiva is a
transparent mucosal
layer that extends from
the corneal junction to
the inner portion of the
eye.
• The Conjunctiva is
divided into 2 parts :
Bulbar & Palpebral.

11. Bulbar conjunctiva
• The Bulbar conjunctiva
is thin ,slightly vascular
and surrounds the eye
ball.

12. Palpebral conjunctiva
• The Palpebral is dense ,
highly vascular and
located in the inner
layer of the lid

13. Tear film
• The tear film have 3 layers :
• Lipid layer : is the outermost
layer and is produced by
Meibomian gland formsa
hydrophobic barrier to trap water
and prevent its evaporation.
• Aqueous (watery) layer : is the
layer between lipid and mucous
layer and contains water and
proteins which has bactericidal
activity.
• Mucus Layer : is produced by
goblet cells found in the
conjunctiva and provide a
hydrophilic layer to ensure the
even distribution of tears.

14. Extra Ocular Muscles
• The extra ocular muscles
spread along the eye ball
and maintains the flexible
movement of the eye .
• There are 7 muscles
a) Palpebral superior
ismuscle
b) Four recti ( superior ,
inferior , medialis
andlateralis)
c) oblique muscles (
superior obliquus and
inferior obliquus muscle
)

15. • Leavtor Palpebral
superioris muscle : thin
muscle that lifts the
upper lid.

16. The rectus muscles
• The superior rectus
enables the upward
movement ,
• The inferior downwards
• The medialis inward
• The lateralis outwards
movement.

17. oblique muscles
• Superior oblique and
• Inferior oblique muscle

18. Eye ball
structures
Fibrous
tunic
Vascular
tunic
Nervous
tunic

20. Fibrous coat
• It consists of two parts
1. Sclera
2. Cornea

21. Sclera
• It is opaque and forms the
posterior five-sixths of the
eyeball.
• It is made of dense fibrous
tissue which is firm and
maintains the shape of the
eyeball. It is thickest
behind, near the entrance
of the optic nerve,
• and thinnest about 6 mm
behind the sclerocorneal
junction

22. • Sclera shows numerous
perforations for passage
of fibres of the optic
nerve.
• Because of its sieve-like
appearance This region
is called the lamina
cribrosa

23. • Outer surface of the sclera is
white and smooth,
• it is covered by Tenon's
capsule
• Its anterior part is covered by
conjunctiva through which it
can be seen as the white of the
eye.
• The inner surface is brown and
grooved for the ciliary nerves
and vessels.
• It is separated from the choroid
by the perichoroidal space
which contains a delicate
cellular tissue, termed the
suprachoroidal lamina .

24. • Sclera is continuous
anteriorly with the cornea
at the sclerocorneal
junction or limbus .
• The deep part of the
limbus contains a circular
canal, known as the sinus
venosus sclerae or the
canal of Schlemm.
• The aqueous humour
drains into the anterior
scleral or ciliary veins
through this sinus.

25. • It provides insertion to
the extrinsic muscles of
the eyeball: The recti in
front of the equator, and
the oblique muscles
behind the equator.

26. Cornea
• Dome shaped , transparent
and non vascularized layer.
• Present over the anterior
1/6th of the eyeball
• Should remain transparent
to ensure correct refraction
of light.
• Serves as a shield against
bacteria , dust and harmful
materials.
• Gets its nourishment from
lymph which circulates in
the numerous corneal spaces

27. Layers of cornea
• Cornea consists of these
layers, from before
backwards:
(a) Corneal
epithelium(stratified
squamous nonkeratinized
type) is
(b) Bowman's membrane
(anterior elastic lamina)
(c) Substantia propria
(d) Descement’s membrane
(e) Endothelium/mesothelium

28. Epithelial layer
• The epithelial layer : is the
outermost layer of the cornea it
includes 5 to 7 layers of epithelial
cells :
1. Squamous cells layer : is covered
by microvilli that absorbs the tears
and keep the epithelial cells
hydrated.
2. The wing cell layer : composed of
wing cells that is attached to each
other via desmosomes which
provide them with communicating
abilities.
3. The basal cell layer : basal cells
play a role in renewing the layer by
multiplication and providing new
wing cells that migrate to change to
new squamous cells which replace
the old squamous layer cells .

29. Bowman’s Membrane
• Bowman’s Membrane :
contains collagen fibers
• and once injured
regeneration is
impossible.

30. Stroma layer
• Thickest layer of the
cornea .
• Contains : 78 % water ,
16 % collagen and
keratocytes.
• It has a unique
arrangement of collagen
fibers in which they
maintain the
transparency of the
cornea.

31. Descemet’s membrane
• The Descemet’s membrane
has 2 different layersin
which the side facing the
stroma have collagen fibers
and the side facing the
endothelium have
endothelial cells .
Descemet’s membrane have
the ability to regenerate
after injury.
• Descemet’s membrane
provide shield against injury
and infection

32. Endothelial layer
• The Endothelial layer is
the innermost layer of the
cornea.
• The Endothelial layer
pumps from the stroma of
any excess fluid and
prevents its swelling
therefore it has a role in
maintenance of a clear
and transparent cornea.
• The Endothelium lacks
the ability to regenerate
after injury.

33. Vascular tunic ( uvea )/ middle coat
• Middle layer of the eye
and is composed of
3 constituents :
• The choroid
• The ciliary body
• Iris

34. Choroid…
• Dark brown tissue.
• Highly vascularized.
• It provides the retina with nutrients and
oxygen.
• The choroid prevents thescattered light from
reaching the retina

35. Choroid
• Is located inferior to the
sclera and superior to
the retina.
• It is a thin pigmented
layer which separates
the posterior part of the
sclera from the retina.
• Anteriorly, it ends at the
ora serrata by merging
with the ciliary body.

36. Structure of choroid
• it consists of:
• (a) Suprachoroidal
lamina .
• (b) Vascular lamina .
• (c) choriocapillary
lamina
• (d) The inner basal
lamina or lamina vitrea
or membrane of Bruch

37. • it consists of: (a) Suprachoroidal
lamina made of collagen fibres,
elastic fibres and pigment cells,
• (b) Vascular lamina composed of
arteries and short posterior ciliary
veins, the latter being arranged in
the form of whorls which converge
to form 4 to 5 venae vorticosae,
loose areolar tissue, and pigment
cells,
• (c) The choriocapillary lamina
forms the most prominent feature
of the choroid. It nourishes the
rods and cones of the retina by
diffusion,
• (d) The inner basal lamina or
lamina vitrea or membrane
ofBruch is a thin structureless
transparent membrane which is
firmly adherent to the outer,
pigmented layer of the retina

38. Cilliary body
• Ciliary body is a
thickened part of the
uveal tract lying
• Just posterior to the
corneal limbus.
• It is continuous anteriorly
with the iris and
posteriorly with the
choroid
• It suspends the lens and
helps it in accommodation

39. 1.The ciliary body is triangular in
cross-section.
It is thick in front and thin behind
• The scleral surface of this body
contains the ciliary muscle.
• The posterior part of te
vitreoussurface is I smooth and
black (pars plana).
• The anterior part is ridged
anteriorly (pars plicata) to
form about 70 ciliary
processes.
• The central ends of the
processes are free and
rounded.

40. Iris
• This is the anterior part
of the uveal tract.
• It forms a circular
curtain with an opening
in the centre, called the
pupil.
• By adjusting the size of
the pupil it controls the
amount of light entering
the eye

41. Iris
• It is placed vertically
between the cornea and the
lens, thus divides the
anterior segment of the eye
into anterior and posterior
chambers, both containing
aqueous humour.
• The anterior surface of the
iris is covered by a single
layer of mesothelium, and
the posterior surface by a
double layer of deeply
pigmented cells

42. • The iris have 2 muscles :
• Sphincter muscles :
contracts in high light
exposure and the pupil
reduces its diameter
allowing less light to pass.
• Dilator muscles :
contracts at low light
exposure and the pupil
will dilate its diameter
allowing more light to
pass.

43. Nervous tunic ( Retina )/inner coat
• This is the thin, delicate inner
layer of the eyeball.
• It is continuous posteriorly with
the optic nerve.
• The outer surface of the retina
(formed by pigment cells) is
attached to the choroid, while the
inner surface is in contact with the
hyaloid membrane (of the
vitreous).
• Opposite the entrance of the optic
nerve there is a circular area
known as the optic disc. It is 1.5
mm in diameter. It is insensitive to
light and is known a Blind spot.

44. • Retina reduces its
thickness from behind
forwards.
• It is divided into optic,
cilliary and iridial parts
• Anterior margin of optic
part is known as ora
serrata beyond which it
is thin and insensitive

45. • 3 mm Lateral to the optic
disc there is another
depression of similar size,
called the macula lutea.
• It is avascular and yellow
in colour.
• The centre of the macula is
further depressed to form
the fovea centralis.
• This is the thinnest part of
the retina. It contains cones
only, and is the site of
maximum acuity of vision

46. • The rods and cones are the light receptors of
the eye.
• The rods contain a pigment called visual
purple and respond to dim light (scotopic
vision). The periphery of the retina contains
only rods,
• The fovea has none at all.
• The cones respond only to bright light
(photopic vision) and are sensitive to colour.

47. Layers of retina
• The retina is composed of ten
layers:
(a)The outer pigmented layer;
(b) layer of rods and cones;
(c) external limiting membrane;
(d) Outer nuclear layer
(e) outer plexiform layer;
(f) inner nuclear layer (bipolar
cells);
(g) inner plexiform layer
(h)ganglion cell layer;
(i) Nerve fibre layer;
(j) The internal limiting
membrane

48. Blood supply of retina
• The retina is supplied by
the central artery.
• This is an end artery. In
the optic disc it divides
into an upper and a
lower branch, each
giving off nasal and
temporal branches.
• Veins run with the
arteries

49. Interior of the eye ball
• The Eye ball is divided
by the lens into 2 parts :
• The anterior cavity .
• The posterior cavity
( the vitreous cavity).

50. Eyeball
• The Anterior cavity includes 2
sections :
Anterior chamber ( between cornea and
iris )
Posterior chamber ( between iris and the
lens )
• Anterior cavity is filled with aqueous
humor. The aqueous humor is rich in
glucose nutrients and respiratory
gases its used to enrichment of the
unvascularized organs.
• The vitreous chamber is filled with
vitreous humour which is colorless
gel like constancy due to the presence
of collagen fibers.
• Vitreous humour also keeps the
retina in place by pushing it against
the choroid.

51. AQUEOUS HUMOUR
• The aqueous humour is
secreted into the posterior
chamber from the
capillaries in the ciliary
processes.
• It passes into the anterior
chamber through the
pupil. From the anterior
chamber it is drained into
the anterior ciliary veins
through the spaces of the
iridiocorneal angle and
canal of schlem

52. Lens
• Lens is a transparent
biconvex structure which
is placed between the
anterior and posterior
segments of the eye.
• It is circular in outline
and has a diameter of 1
cm.
• The central points of the
anterior and posterior
surfaces are called the
anterior and posterior
poles

53. • The posterior surface of the lens is more
convex than the anterior.
• The lens is enclosed in a
transparent,structureless elastic capsule
• Deep to capsule, the anterior surface of the
lens is covered by a capsular epithelium.

54. Structure of lens
• The lens is made up of 3
parts :
• Nucleus
• Capsule
• Cortex
• suspensory ligament of
the lens (or the zonule of
Zinn) retains the lens in
position and its tension
keeps the anterior surface
of the lens flattened

55. Vitreous humour
• It is a colourless,
jellylike transparent
mass
• fills the posterior
segment (posterior
4/5th) of the eyeball.
• It is enclosed in a
delicate homogeneous
hyaloid membrane.

56. CLINICALANATOMY
• Eye is a very sensitive organ and even a dust
particle gives rise to pain.
• Cornea can be grafted from one person to the
other, as it is avascular.
• Injury to cornea may cause opacities. These
opacities may interfere with vision.

57. • Overproduction of
aqueous humour or lack
of its drainage or
combination of both
raise the intraocular
pressure. The condition
is called glaucoma.

58. • Central artery of retina
is an end-artery.
Blockage of the artery
leads to sudden
blindness.

59. • Bulbar conjunctiva is
vascular. Inflammation
of the conjunctiva leads
to conjunctivitis.
• The look of palpebral
conjunctiva is used to
judge haemoglobin
level.

60. • Anteroposterior
diameter of the eyeball
and shape and curvature
of the cornea determine
the focal point.
• Changes in these result
in myopia or short-
sightedness,
hypermetropia or
longsightedness,

61. • Lens become opaque by
age it is known as
cataract.
• Opacities cannot be
removed so lens has to
be replaced.