The eyeball has three coats - fibrous, vascular and nervous. The fibrous coat has the sclera and cornea. The cornea is avascular and has 6 layers. The sclera is thick posteriorly. The vascular coat has the uvea with iris, ciliary body and choroid. The iris controls the pupil and ciliary body secretes aqueous humor. The choroid supplies the outer retina. The nervous coat has the retina with rods, cones and ganglion cells. The lens is behind the iris and held by zonules. The retina contains the macula and optic disc.

1. ANATOMY OF
EYE

2. EYE BALL
• Cystic structure distended by
intraocular pressure
• Shape : refered to as a globe
but is an oblate spheroid ( 2
modified spheres one infront
of another)
• Poles : center point on
maximal convexities of
anterior and posterior
curvature. 2 poles

3. • Equator : midplane
between the two poles
• Dimentions :
AP – 24mm
HZ – 23.5mm
VT – 23mm
Circumference – 75mm
• Volume – 6.5ml
• Wt – 7g

4. GLOBE
• LAYERS –
 FIBROUS COAT :
ant 1/6th transparent-cornea
Posterior 5/6th opaque-sclera
Junction of cornea & sclera- limbus
VASCULAR COAT :
Supplies nutrition to various structures
uvea (choroid, ciliary body, iris)
NERVOUS COAT:
Concerned with visual function
retina  sensory & pigment

5. SEGMENTS AND
CHAMBERS
ANTERIOR
SEGMENT
STRUCTURES ANT
TO LENS
ANTERIOR CHAMBER
ANT- BACK OF CORNEA
POST- ANT SURFACE OF IRIS & PART
OF CILIARY BODY
AC- 2.5MM DEPTH
2.5ML – AQUEOUS
COMMUNICATES WITH PC
THROUGH PUPIL
POSTERIOR CHAMBER
TRIANGULAR SPACE
CONTAINS 0.6ML –
AQUEOUS
ANT- POST SURFACE OF IRIS
& PART OF CILIARY BODY
POST- LENS & ITS ZONULES
LATERALLY- CILIARY BODY
MEDIALLY-LENS EQUATOR
POSTERIOR
SEGMENT
STRUCTURES
POSTERIOR TO LENS;
VITREOUS , RETINA,
CHOROID & OPTIC
DISC

7. CORNEA
• Transparent, avascular watchglass like
• Anterior 1/6th of eyeball
• Elliptical anteriorly HZ – 12mm, VT – 11mm
• Circular posteriorly 11.5mm diam
• Thickness – 0.5mm CENTRE
0.8-1MM PERIPHERY
• Refractive index – 1.37
• Diopteric power - +43 D to + 45D
• Radius of curvature – Anterior 7.8mm
Posteriorly 6.5mm

8. Layers of cornea: 6
1. Stratified squamous epithelium
- 5-6 cell deep, continuous
with conj. Epith
- basal cells tall with oval
nuclei
- intermed (2-3 cells deep;
polyhedral wing cells)
- surface (about 2 ); flat- non
keratinised
- rests on basement
membrane
2. Bowman’s layer
- anterior elastic lamina
(condensation of substantia
propria)
- does not regenerate–leaves
scar

9. 3. Stroma (substantia propria)
- 90% of corneal thickness
- collagen fibrils in parallel sets
of lamellae
- crystalline lattice
- ground substance -
glycoprotein and
mucopolysaccharides
- keratocytes , wandering
leucocytes and macrophages
4. Dua’s layer ( pre descemet
layer)
- by Harminder singh Dua et al.
15microns thick
- impervious to air, very strong

10. 5. Descemet’s membrane
(Posterior elastic lamina)
- strong, resistent,
regenerates after injury
- Secreted by endothelial
cells
- Hassall – Henle’s bodies
(warty elevations in old
age)
6. Endothelium
- single layer , flat
polygonal endothelial cells
- continuous with
endothelium over anterior
surface of iris
- does not regenerate

11. • NERVE SUPPLY
- From long and short ciliary nerves ( trigem N)
- form pericorneal plexus outside limbus and pass
onto cornea as 60-70 trunks
- loose their myelin sheath after 1-2mm and reach
cornea
(Cornea doesn’t have proprioceptive sensation)
• BLOOD SUPPLY
- avascular
- limbus supplied by perilimbus plexus from
anterior conjunctival branches of anterior ciliary
arteries.

12. SCLERA
• Post. 5/6th of eye
• 2 windows – ant. for cornea
- post. for optic nr
Structures piercing :
1. 4 vortex veins (4mm behind
equator)
2. Long and short ciliary nerve and
vessels
3. Anterior ciliary nerve and vessels
Thickest posteriorly surrounding optic
nerve (1mm)
Thinnest posterior to insertion of recti
muscles (0.3mm)

13. Structures:
1. Episclera : loose fibrous tissue, containing
numerous fine capillaries
2. Sclera proper : Dense collagen fibre network,
irregular arrangement hence white
3. Lamina fusca : inner layer adjacent to choroid
Blood supply : episcleral and choroidal vessels
Nerve supply : Short ciliary nerve posteriorly,
long cilliary anteriorly. Hence inflammation is
painful.

14. LIMBUS
• Zone between cornea and sclera
• 1-2mm wide
• Internal boundaries – scleral spur posteriorly and
schwalbe’s line
• External boundaries – sclerolimbal junction
posteriorly(consistent landmark) corneolimbal junction
anteriorly
• Contains trabecular meshwork internally, through which
aqueous humour leaves anterior chamber

15. ANGLE OF ANTERIOR CHAMBER
• Normal wide open angle – 20-45 degree
• Boundaries
Anteriorly – cornea
Posteriorly – ant surface of iris and part of ant surface of
lens exposed at pupil
• Peripheral recess of anterior chamber is angle of
anterior chamber ( aka cockpit of glaucoma)
• Sclemm’s canal is present in inner layers of sclera here
• Trabecular meshwork is between sclemm’s canal and
recess of anterior chamber
• Best visualised on gonioscopy
• Angle < 10 degree chances of developing Angle closure
glaucoma

17. UVEA
3 parts
• ANTERIOR : Iris
• INTERMEDIATE : Ciliary body
• POSTERIOR : Choroid
Function:
• Iris with central opening pupil controls amount of light
entering
• Ciliary body secretes aqueous humour and has zonules
suspending the lens hence changing shape for
accomodation
• Choroid, vascular layer- blood supply to retinal pigment
epithelium layer and outer half of sensory retina

19. Iris and Pupil
• Iris lies in front of lens & ciliary body
• Separates ant chamber from post chamber
• Periphery/ root of iris attatched to ciliary body
• Anterior surface divided into
1. Central pupillary zone
2. Peripheral ciliary zone junction : collarette

20. Structure:
1. Anterior epithelium: continous
with corneal endothelium
2. Stroma – CT, nerves, blood
vessels, smooth muscles
3. Smooth muscles :
-Sphincter pupillae - circular
-Dilator pupillae - radially
Posterior two layered epithelium
Ant- flattened cells
Post- cuboidal cells
Nerve supply -
sensory: Nasociliary Nerve
Sphincter pupillae : 3rd nerve
Dilator pupillae : cervical
sympathetic chain

21. CILIARY BODY
• Ring of tissue 6mm wide extending from scleral spur to orra
serrata of retina
• Structure:
Ciliary muscles (unstriped) – longitudinal, circular , radial
Inner surface : Pars plicata – produce aqueous humour (ant)
Pars plana – avascular zone ; safe for PPV and
lensectomy
• Extends upto orra serrata.
• Nr supplySensory – Nasociliary br of 5th CN
Ciliary muscles–3rd nerve and sympathetic nerve
• Blood supply – 2 long posterior ciliary arteries and 7 anterior
ciliary (major circle)

22. • Function
1. Formation of aqueous humour by ciliary process
2. Ciliary muscles help in accomodation for near work
3. Ciliary muscles help in opening up the schlemm’s canal
and thus faciitate the aqueous outflow

23. CHOROID
• Vascular sheet separates sclera from
Retina.
• 0.25mm thick at posterior pole & 0.1mm
thick anteriorly
• Attatched firmly to sclera around the optic
nerve and at points of exit of vortex veins.

24. • 3 vessel layer:
1. Outer vessel layer (of
Haller) : nearest to
sclera; large veins that
lead to vortex veins
2. Middle vessel layer (of
Sattler) : medium sized
veins & arterioles, with
fibrous tissue
3. Inner choriocapillaries:
large fenestrated
capillaries

25. • Bruch’s membrane: 7micrometre thick; separates
choriocapillaries from RPE
• Important for blood retinal barrier function
• 5 layers:
1.Basement membrane of choriocapillaries
2. Outer collagen layer
3. Middle elastic layer
4. Inner collagen layer
5. Basement membrane of RPE
BLOOD SUPPLY – Short posterior ciliary arteries
2 long posterior ciliary arteries
Anterior ciliary arteries
Venous : Vortex viens  sup and inf ophthalmic viens 
cavernous sinus

26. LENS
• Transparent, biconvex
• Diam : 9mm, thick: 4mm,
• Radius of curvature - Ant :10mm , Post : 6mm
• Ref. index : 1.39
• Total diopteric power : +16 to +20 D
• Lens is held by suspensory ligaments – zonules
of zinn

27. STRUCTURE
1. Lens capsule :
-smooth, homogenous, highly elastic( no
true elastic tissue)
- thickest(14u)- ant & post surface just
central to insertion of zonular fibres
-thinnest(3-4u)- posterior pole
2. Lens epithelium:
- single layer
-cuboidal cells
-no corresponding posterior epithelium
3. Lens substance : cortex & nucleus
-embryonic nucleus: 1st 3 months of
fetal life
- fetal nucleus: 3-8 months of fetal life
- infantile nucleus- upto puberty
- adult nucleus- rest of life

28. RETINA
• Membranous light sensitive coat of eyeball
• Life- transparent
• After death- whitish
• Derived from inner & outer layer of
embryological cup

29. STRUCTURES
MICROSCOPIC STRUCTURE OF RETINA

30. • RPE : single layer, flattened hexagonal cells,
cells contain melanin, choroidal ring
• LAYER OF RODS & CONES: Rods- 125 million,
Cones- 7 million
• EXTERNAL LIMITING MEMBRANE: thin
lamina, formed by supporting fibres of Muller
• OUTER NUCLEAR LAYER: Rod & cone nuclei

31. • OUTER PLEXIFORM LAYER: formed by
anastomoses of photoreceptor cells with
bipolar & horizontal cells, rod spherules &
cone pedicles
• INNER NUCLEAR LAYER: nuclei of bipolar,
horizontal, amacrine cells, Muller’s fibres
• INNER PLEXIFORM LAYER: arborization of the
bipolar cells with the ganglion cells &
amacrine cells

32. • GANGLION CELL LAYER: cell bodies of ganglion
cells. 2 types of ganglion cells :
• MIDGET GANGLION CELLS : present in ganglion region
• POLYSYNAPTIC GANGLION CELLS: present in peripheral
retina
• NERVE FIBRE LAYER: stratum opticum, consists of
axons of the ganglion cells which pass through
the lamina cribrosa to form optic nerve
• INTERNAL LIMITING MEMBRANE: thin lamina,
separates retina from vitreous; formed by union
of terminal expansions of Muller’s fibres;
essentially basement membrane

33. REGIONS
1. ORA SERRATA: ant termination of retina,
8mm from limbus; 2 layers of primitiv optic
vesicle fuse & continue forward  ciliary
epithelium
2. CENTRAL RETINA: 4 .5mm diameter; extends
from fovea centralis almost to optic disc;
central part of this region- macula lutea
(contains xanthophyll)

34. • FOVEA CENTRALIS :
• depressed area
• located in central retina
• 3mm temporal to optic
disc & 0.8mm below
horizontal meridian
• measures 1.5mm
• central depression  foveola(0.5mm)
• Fovea nourished by choriocapillaries of choroid;
does not contain vessels, (FOVEOLAR AVASCULAR
ZONE)

35. 3. PERIPHERAL RETINA : photoreceptors mainly
rods; larger ganglion cells  their cell bodies
arranged in a single layer
temporal
4. FUNCTIONALLY : retina (by a vertical line through centre
of the fovea)
nasal
5. OPHTHALMOSCOPICALLY: superior, inferior,
temporal, nasal, central retina

36. BLOOD SUPPLY
• OUTER PORTION:- choriocapillaries
• INNER PORTION:-mainly by central retinal
artery

37. CONJUNCTIVA
• Mucous membrane covering inner surface of
the eyelids
• Reflected to cover the anterior part of eyeball
over the sclera  upto corneal margin

38. PARTS
• PALPEBRAL : consistes
of marginal, tarsal &
orbital part; firmly
adherent to deeper
tissue
• BULBAR: lies over
sclera; freely mobile
• FORNIX: cul-de-sac at
the junction of palpebral
& bulbar conjunctiva
• LIMBAL: conjunctiva at
the corneal junction
which is adherent

39. • NERVE SUPPLY- Ophthalmic division of
trigeminal nerve
• ARTERIAL SUPPLY-
– ant conjunctival artery from the anterior
ciliary artery
–Posterior conjunctival artery from the
lacrimal artery
–Palpebral branch of nasal artery

40. TENONS CAPSULE
• Thin membrane
• Envelops eyeball from optic nerve to the
limbus
• Thickening of lower part of tenon’s capsule –
suspensory ligament of eye( of Lockwood)

41. EYELID

43. EXTRA OCULAR MUSCLES
MUSCLE ORIGIN INSERTION NERVE
SUPPLY
ACTION
SUPERIOR
RECTUS
7.7 MM FROM
LIMBUS
3RD CN ELEVATION ON
ABDUCTION &
INTORSION
LATERAL
RECTUS
ANNULAR
TENDON OF ZINN
6.9MM FROM
LIMBUS
6TH CN
(ABDUCENS)
ABDUCTION
INFERIOR
RECTUS
(AROUND OPTIC
FORAMEN AT
THE APEX OF
ORBIT)
6.6MM FROM
LIMBUS
3RD CN
(OCCULOMOTOR)
DEPRESSION ON
ABDUCTION &
EXTORSION
MEDIAL
RECTUS
5.5MM FROM
RECTUS
3RD CN ADDUCTION
SUPERIOR
OBLIQUE
APEX OF ORBIT
FROM ANNULAR
TENDON OF ZINN
IN SCLERA AT
SUPEROLATERAL
PART
4TH CN
(TROCHLEAR)
DEPRESSION ON
ADDUCTION &
INTORSION
INFERIOR
OBLIQUE
ANTERIORLY
FROM LOWER &
INNER ORBITAL
WALL NEAR
INFEROLATERAL
PART OF SCLERA
3RD CN ELEVATION ON
ADDUCTION &
EXTORSION

44. EXTRA OCULAR MUSCLES

45. INTRINSIC MUSCLES OF THE EYE
• CILIARY MUSCLES
ORIGIN- scleral spur
INSERTION- ant 1/3rd choroid
NERVE SUPPLY- Parasympathetic innervation from short ciliary nerve
ACTION- accomodation
• SPHINCTER PUPILLAE
ORIGIN- pupillary margin of iris
INSERTION-
NERVE SUPPLY- 3rd nerve
ACTION- constricting the pupil
• DILATOR PUPILLAE
ORIGIN- outer margin of iris
INSERTION- inner margin of iris
NERVE SUPPLY- cervical sympathetic chain
ACTION- dilating the pupil

46. THANK YOU !