1. TOPIC NAME

4. STRUCTURE OF EYE
Orbital cavity Iris
Eye lids Choroid
Eye ball Cilliary body
Conjunctiva Aqueous humor
Lacrimal gland limbus
Cornea vitreous humor
Sclera
Ratina
Pupil
Lens

6. ORBITAL CAVITY
“The bony cavity in skull containing the eye ball and it's
associated muscles, vessels and nerves also called eye
sockets, orbit ”
FUNCTIONS
 It serves as a cushion to protect eye ball
from external force.

8. EYELIDS
 "The layer of skin covers and protect the eye it has thinnest skin of whole body"
 Functions
 protect and lubricate the eye
 blink and keep eye moist
 cut of light during sleep
 protect eye from dust particles and perspiration
 wipe eye and prevent dehydration
 fighting bacterial infection

9. palpebrae protects eye
Eyelashes trigger blinking
Levator palpebrae superioris raises eyelid
Eyebrows
Shade the eyes
Prevent perspiration into eye

11. CONJUNCTIVA
 " it is thin mucous membrane which covers the exposed part of eye "
 After covering the anterior surface the conjunctiva is reflected to the
 inner part of eyelids
 functions
 keep the eye moist by sliding the opposite portion of conjunctiva
 balbur portion palpebral portion
 balbur fissura palpebral fissura

13. EYE BALL
The globe-shaped portion of the eye surrounded by the
socket and covered externally by the eyelids.
Diameter 1 inch (2.5 cm) in diameter
Weight 7.5 gm

15. WALLS OF EYEBALL IS
COMPOSED OF THREE
LAYERS
1) Outer layer which include cornea and sclera
2) Middle layer which include choroid cilliary body and iris
3) Inner layer ,the retina

17. CORNEA
 "cornea is the transparent convvex anterior portion of outer layer of
the eye ball which cover the iris and pupil"
 or
 cornea is front window of eye that transmit and fucuses the light into
eye
 size
 0.5 mm thick at center and 1to 2 mm thick at periphery

18.  diameter
 12mm horizontally and 11 mm vertically
 cornea has a refractory index of 1.376
refractory index
 function
 it focuses light into eye

20. SCLERA
 Sclera is the tough white fibrous outer layer of the eye ball that
cover posterior 5/6 of the eye anteriorly it is continuous with
cornea
 Lamina cribrosa
 The posterior part of the sclera where it is pierced by the optic
layer is thin with perforation it is name as lamina cribrosa

22. MIDDLE LAYER
 Choroid
 Cilliary body
 Iris
Choroid is the thin vascular layer of eye ball situated between sclera and retina it
form posterior 5/6 of middle layer
►choroid is composed of the a rich capillary plexus, numerous small arteries and
veins

23. CILLARY BODY
 Cillary body is thickened anterior part of middle layer of eye situated between
choroid and iris
 It is in the form of ring
 Cillary body has three parts
i. Orbiculus ciliaries
ii. Ciliary body proper
iii. Ciliary processes

25. IRIS
 Iris is the colored curtain like structure of eye ball it form
the anterior most part of the middle layer it is like a thin
circular diaphragm place in the front of lens
 It is a muscular has two muscles
 constrictor pupillae
 Dilator pupillae

26. PUPIL
it is a hole located in the Centre of iris and pupil is also
central transparent area of the eye.
function
the pupil modifies the amount of light entering into it.

28. INNER LAYER
THE RATINA
ratina is a thin delicate membrane which photoreceptor and
a layer of nerve fiber which are continous with the optic nerve.
location...;it is placed between the vitrous internally and
choroid externally

30. FUNCTIONS
1)retina act as a receptor mechanism of the eye and ultimate tool
of vision light and color sensitive element of the ratina
communicate their message via neural pathway to the visual cortex
of the brain.
2)ratina also play a role in light reflex and accommodation reflex.
3)ratina impulses also help to maintain the tone, posture and
equilibrium of the body.

31. PHOTORECEPTOR
there are two photoreceptors in ratina
1)rod ....responsible for dark vision
2)cone......... responsible for colour vision

33. LENS
 it is a transparent, biconcave, elastic body that lies between iris and vitrous body.
 structure of lense
 it is formed of three components
 1)the capsule.
 2)the anterior epithelium.
 3)the lens substance.
 composition...
 in young; 69% water and 30% protein.....
 in old age; decreases water %age, increase protein %age
 lense also contain potassium, sodium, chlorin, ascorbic acid and glutathione.

34. FUNCTIONS
 1)lens refracts light and focus it on the ratina
 the focal length of human lens is 44mm and its refractory power is 23D

35. INTRAOCULAR FLUID
The fluid in the eyeball responsible for
maintenance of shape of the eyeball…….
The two type of fluids are present in the
eyeball……
1)aqueous humor
2)vitreous humor

36. AQUEOUS HUMOR
 it is a thin clear, colorless, transparent fluid present in the
anterior(chamber between cornea and iris) and posterior
chamber(chamber between the iris and lens) of the eyeball.
 normal intraocular pressure is 16-22mmHg
 composition of aqueous humor...
 98.7% water (organic
substances.....albumin,globulin,glucose,pyruvate,lactate,urea) , solids
1.3%(inorganic substances......sodium, calcium, potassium, magnesium,
chlorides, phosphates, bicarbonates)

37. FUNCTIONS
1) maintain the intraocular pressure.
2)supply nutrition to avascular structure like cornea and lens.
3)act as refractory medium.
4)act as a barrier.
5)remove the metabolic end products from lens and cornea.

39. VITREOUS HUMOR
vitreous humor is a viscous fluid present behind the lens in
the space between the lens and ratina. it is a highly viscous
and gelatinous substance.
 it is also known vitreous body
 the major substances in it are albumin and hyaluronic acid
these substances enter vitreous body from blood by mean of
diffusion

40. FU NC TION
1)it helps maintain the shape of the eyeball.

41. GLAUCOMA
 it is a group of diseases characterized by increased intraocular pressure which
causes damage of optic nerve resulting in blindness
 types
 Congenital glaucoma
Infantile glaucoma juvenile glaucoma
 causes of glaucoma
 1)blockage in drainage system.
 2)increase intraocular pressure.

42.  glaucoma also develops secondary to other disorders which effect the eyes
 common causes are.
 1)diabetes 2)inflammation
 3)injury to eye 4)excess use of drugs e.g. corticosteroid
Treatment
treatment does not cure the diseases but can prevent further damage of optic
nerve it is aimed as lowering the intraocular pressure it is achieved by using
eye drops or medicine alone or in combination with laser treatment. If
intraocular pressure dose not controlled by these methods surgery is required

44. CATARACT
 cataract is the opacity or cloudiness in the natural lens of the eye
 it is major cause of blindness worldwide. When the lens become cloudy. Light rays
cannot pass through it easily and vision is blurred
 it develops in old age after 55-60years
 causes
 1)eye injuries. 2)previous eye surgery
 3)diabetes 4)hypocalcemia
 5)long term use of drugs 6)long term unprotected exposure to sunlight
 7)alcoholism 8)family history
 9)diet containing large quantity of salt

45. SYMPTOMS
 1)glare
 2)painless blurred vision 3)poor night vision
 4)diplopia in affected eye 5)need for a bright light while
reading
 6)fading of color
treatment
 surgery is only treatment for this

47. REFRENCE
Essential of Medical Physiology by
Jaypee (5th edition) chapter no.165… page
no. 924, 25,26,28,,29,30,33,34.
2)Notes of sir Tabish
3)Medical dictionary(Internet)