1. Anatomy Of Eye Mohammad Ali A Sadiq, M.D
F.C.P.S (Pk) F.P.O.S (UK) F.A.A.P.O.S (Harvard)
Assistant Professor of Ophthalmology
King Edward Medical University

3. EYE Asymmetrical globe about an inch in diameter (24mm)
Cornea (Clear dome over the iris)
Conjuctiva (thin layer of tissue covering the front of eye)
Sclera (White part)
Iris (pigmented part)
Pupil

4. EYE Lens – behind the iris and pupil
Focus light on the back of the eye
Vitrous – Gel filling the eye
Retina – special light sensing cells
Converts light into
electrical impulses
Macula – small sensitive
Area in the center of retina
Optic Nerve –carries
Impulses to the brain

5. Eyelid Thin fold of skin that covers and protects the human eye.
FUNCTIONS
Regularly spread the tears and other secretions of the eye surface.
Responsible for corneal protection
Responsbile for corneal nutrition
Lashes provide additional protection

6. Eyelid LAYERS Skin Sweat glands Sebacoues glands Hair – eye lashes
Subcuatneous tissue
Orbicularis Oculi muscle
Orbital septum
Aponeurotic fat
Levator palpebrae superioris
Muller muscle
Tarsal Plate
Palperbral Conjuctiva

7. Lacrimal system LACRIMAL GLAND PUNCTI LACRIMAL CANALICULI LACRIMAL SAC
Secretes tears
PUNCTI
0.3mm in diamter
Sits on an elevated mound –
papilla lacrimalis
Relatively avascular
LACRIMAL CANALICULI
Initial vertical segment – 2mm
Horizontal segment -- 8mm
Valve of Resonemuller
LACRIMAL SAC
Fundus – 3-5 mm
Body – 10 mm
NASOLACRIMAL DUCT
12mm Intraosseous portion
5 mm inferior membranous portion
Valve of Hassner

8. CORNEA
Transparent from part of the eye covering the Iris, pupil and Anterior chamber
Accounts for Approx 2/3rd of the refractive power of the eye (43 Diopters)
Completely avascular – recieves nutrients via diffusion from the tear film and aqueous humor
Unmyelinated nerve endings sensitive to

9. CORNEA Diameter – 11.5 mm Thickness Layers 0.5-0.6 mm in the center
mm in the periphery
Layers
Corneal Epithelium – non keratinized stratified sq cells
Bowmans Layer – Anterior limiting membrane (Type 1 collagen fibrils)
Corneal Stroma – regularly arranged collagen fibrils with keraotcytes (Type 1 collagen fibrils)
Descement’s membrane – Posterior limiting membrane (Type 1 and 4 collagen fibrils)
Corneal Endothelium simple squamous or low cuboidal monolayer

10. AQUEOUS HUMOR
Transparent, gelatinous fluid similar to plasma but low in protein.
FUNCTIONS:
Maintains the IOP
Provided nutrition to
Cornea
Trabecular meshwork
Lens
Anterior Vitrous
Presence of
Immunoglobulins
Refractive Index

11. AQUEOUS HUMOR
Secreted into the posterior chamber by the ciliary body – pars plicata
Drains out of the eye through the trabecular meshwork
Then into the schlem canal
Directly into episcleral vein
Indirectly through collector
channels

12. Conjuctiva Lines the inside of the eyelids and covers the sclera
Non keratinized stratified epithelium with goblet cells
FUNCTION
Helps lubricate the eye by producing mucus and lacrimal gland
Contributes to immune surveillance of the eye

13. Conjuctiva Palpebral or Tarsal conjuctiva Bulbar or Ocular Conjuctiva
Lines the eyelid
Bulbar or Ocular Conjuctiva
Covers the eyeball over the sclera
Tightly bound to underlying sclera by Tenon’s capsule
Moves with eyeball movement
Fornix Conjuctiva
Junction between bulbar and Palpebral conjuctiva
Loose and flexible

14. Sclera Forms the supporting wall of the eyeball
Continuous with the clear cornea
Thickest in the area surrounding the optic nerve
Thinnest at the insertion of the muscle

15. SCLERA Three Divisions Episclera Sclera Proper Lamina Fusca
Loose connective tissue immediately beneath the conjuctiva
Sclera Proper
Dense white tissue that gives the area its colour
Lamina Fusca
Inner most zone made up of elastic fibres

16. IRIS
Thin, circular structure in the eye responsible for controlling the diameter and size of the pupil
TWO LAYERS
Storma
Front pigmented fibrovascular layer
Connects to
Spincter muscle – sphincter pupillae
Dilator muscle – Dilator pupillae
Pigmented Epithelial cells
Two cell thick

17. IRIS Outer edge of the iris is attached to
Sclera
Anterior ciliary body
IRIS AND CILIARY BODY TOGETHER ARE KNOWN AS ANTERIOR UVEA
PORTIONS OF THE IRIS
Pupillary zone – inner region whose edge forms the boundary of the pupil
Cilliary Zone – rest if the iris that extends to its origin at the ciliary body
Collarette – region when the sphincter and dilator muscle overlap

18. LENS Transparent bi-convex structure
Helps in refracting light (18 diopters) – one third of the eyes total power
Ability to change shape – Accomodation
Suspended in place by the suspensory ligaments
10 mm in diameter.
Axial length of 4mm

19. LENS COMPONENTS OF LENS LENS CAPSULE LENS EPITHELIUM LENS FIBERS
Smooth transparent basement membrane
Elastic membrane composed of collagen (type 4)
Varies from 2 to 28 micrometers – thickest at the equator
LENS EPITHELIUM
Anterior portion of the lens between the capsule and lens fibers
Simple cuboidal epithelium
Regulates most of the homostatic functions of the lens
Progenitor for new lens fibers
LENS FIBERS
Bulk of the lens
Long, thin , transparent cells, firmly packed.
Diameters typically 4-7 microns and length upto 12 mm

20. VITROUS Clear gel filling the space between retina and the lens
Remains unchanged throughout life
Produced by cells in the non pigmented portion of the ciliary body
98-99% of the body is water
Strongly connected to the optic disc and the orra serrata
Loosely connected to the macula and blood vessels
As human ages, it liquefies and often collapses

21. CHOROID Thin vascular layer between the sclera and the retina
Supplies blood to the retina and conducts arteries and nerves to other structures in the eye
FOUR LAYERS
Haller’s layer – outermost layer consisting of large blood vessels
Sattler’s layer – layer of medium diameter blood vessles
Choriocapillaris – layer of capillaries
Bruch’s membrane – Inner most layer of the choroid

22. RETINA L atin word “rete” meaning net
Inner most, light sensitive layer of the eye
Light striking the retina initiates a cascade of chemical and electrical events that trigger a nerve impulse
PHOTORECEPTOR CELLS
RODS
Dim light
Black and white vision
CONES
Suuport day time vision
Colour perception
Ganglion cells
Reflexive response to bright daylight

23. RETINA LAYERS OF RETINA Inner Limiting membrane
Nerve Fiber layer – axons of ganglion cell nuclei
Ganglion cell layer
Inner Plexiform layer – Contains synapses between bipolar axons and denrites of ganglion and amacrine cells
Inner Nuclear Layer – contains the nuclei of amacrine cells
Outer pelxiform layer – projections of rods and cones
Outer nuclear layer – cell bodies of rods and cones
External limiting membrane layer – layer that separates the inner segment portions of the photoreceptors from their cell nucleus
Layer of rods and cones
Retinal Pigment Epithelium - single layer of cuboidal cells. This is closest to the choroid.

24. EXTRA-OCULAR MUSCLES 6 Extra-ocular muscles 4 Rectus muscles
2 Oblique muscles
M.R – 5.5mm from limbus
I.R ``– 6.5 mm
L.R mm
S.R mm

25. OPTIC NERVE Extension of the brain
Energy transmission from retina to the brain
Subject to underdevelopment, damage. Inflammation
Over 1 million nerve fibers
Once it is severed, it cannot be reconnected

26. THANK YOU