detailed ocular anatomy

1. EYE
G KARTHIK KUMAR
M OPTOM
Asst. Prof
MLRU

2. ANATOMY OF THE EYE

3. THE EYEBALL/GLOBE
Each eyeball is a cystic structure kept distended by the pressure inside it.
Oblate spheroid.
anterior and posterior pole.
The equator of the eyeball lies at the mid plane between the two poles.

4. Dimensions of an adult eyeball
Anteroposterior diameter 24 mm
Horizontal diameter 23.5 mm
Vertical diameter 23 mm
Circumference 75 mm
Volume 6.5 ml
Weight 7 gm

5. Coats of the Eyeball
1. Outer (Fibrous coat)
2. Middle (Vascular coat)
3. Inner (Nervous coat).

6. 1.Fibrous coat.
 It is a dense strong wall which protects the intraocular
contents.
 Anterior 1/6th is transparent
called cornea.
Posterior 5/6th opaque part is
called sclera.
 Junction of the cornea and sclera is called limbus.
Conjunctiva is firmly attached at the limbus.

7. 2.Vascular coat (Uveal Tissue).
It supplies nutrition to the various structures of the eyeball.
It consists of three parts which from anterior to posterior are :
Iris
Ciliary Body
Choroid.

8. 3. Nervous coat
(Retina).
It is concerned with
visual functions.

9. Segments and chambers of the eyeball
1)Anterior segment:
a)Cornea
b)Iris
c) crystalline lens
d)Ciliary body
e)Zonules
f)Two aqueous humour-filled spaces :
Anterior and Posterior chambers.
2. Posterior
segment :
a) Vitreous humour (a gel like material
which fills the space behind the
lens).
b) Retina
c) Choroid
d) Optic disc.

10. Anterior chamber:
It is bounded anteriorly by the back of
cornea, and posteriorly by the iris and part
of ciliary body.
The A/C is about 2.5 mm deep in the
centre in normal adults.
It contains about 0.25 ml of the Aqueous
Humour.
It is Shallower in hypermetropes and
Deeper in myopes.
Posterior chamber:
It is a triangular space containing 0.06 ml
of aqueous humour.
It is bounded anteriorly by the posterior
surface of iris and part of ciliary body.
Posteriorly by the crystalline lens and its
zonules.