The eye has three layers - an outer fibrous layer, middle vascular layer, and inner nervous tissue layer. It contains structures like the lens, aqueous humor, and vitreous humor. The sclera forms the outer layer and continues as the transparent cornea. The choroid lines the inner eye and contains blood vessels. The ciliary body continues from the choroid and contains muscles and secretory cells. The iris divides the eye chambers and its color is visible. The lens refracts light and changes thickness to focus on objects. The retina contains nerve cells and is stimulated by light. Blood supply comes from the retinal and ciliary arteries.

1. VISIO
N
COVERED BY
DEEPAK KUMAR

2. VISION
The eye is the organ of the
sense of sight
Situated in the orbital cavity
and it is supplied
By the optic (2nd cranial nerve
).

4. Structure :
There are three layers of tissue in the walls of the
eye.
They are.
1.The outer fibrous layer : sclera and cornea
2.The middle vascular layer or uveal tract :
choroid , ciliary body and iris
3.The inner nervos tissue layer : retina .
Structures inside the eyeball are the lens ,
aqueous fluid
( humour ) and vitreous body ( humour ) .

6. Sclera
The sclera, or white the eye, forms the outermost
layer of tissue of the posterior and lateral aspects of
the eyeball and is continuous anteriorly with the
transparent cornea .
It consists of a firm fibrous membrane that shape of
the eye and gives attachment to the extraocular or
extrinsic muscles of the eye.

7. Cornea
Anteriorly the sclera continues as a clear
transparent epithelial membrane ,the cornea.
Light rays pass through the cornea to reach
the retina .
The cornea is convex ante - riorly and is
involved in refracting or bending light rays to
focus them on the retina .

8. Choroid
The choroid lines the posterior 5 - 6 of the inner
surface of the sclera .
It is very rich in blood vessels and is deep
chocolate brown in colour .
Light enters the through the pupil ,stimulates the
nerve endings in the retina and is then absorbed by
the choroid .

9. Ciliary
Body
The ciliary body is the anterior continuation
of the choroid consisting of ciliary muscle
(smooth muscle fibres ) and secretory
epithlial cells.
It gives attachment to the suspensory
ligament which ,at its other end ,is attached
to the capsule enclosing the lens

10. Iris
The iris is the visible coloured part of the
eye and extends anteriorly from the ciliary
body, lying behind the cornea in front of
the lens
It divides the anterior and posterior
chambers which contain aqueous fluid
secreted by the ciliary body .

11. Lens
The lens is a highly elastic circular
biconvex body, lying immediately behind
the pupil
The lens bends (refracts) light rays
reflected by objects in front of the eye .
The nearer is the object being viewed the
thicker the lens becomes to allow
focusing .

12. Retin
a
The retina is the innermost layer of the wall of
the eye it is an extremely delicate structure and
is especially adapted for stimulation by light
rays
It is composed of several layers of nerve cell
bodies and axons ,lying on a pigmented layer
of epithelial cells which attach it to the choroid .

14. Bood Supply
The eye is supplied with arterial blood by the
ciliary arteries and the cential retinal artery .
Venous drainage is by a number of
veins,including the central retinal vein ,which
eventually empty into a deep venous sinus .
The central retinal artery and vein are encased
in the optic nerve, enteing the eye at the optic
disc .

15. Physiology of
sight
Light waves travel at a speed of 186000 miles
(300000 kilo metres) per second .
Light is reflected into the eyes by objects
within the field of vision .
White light is a combination of all the colours
of the visual spectrum (rainbow)
Ex: red ,orange, yellow ,green ,blue , indigo ,
and violet.

16. Extraocular Muscles of the
Eye :
Medial rectus
Lateral rectus
Superior rectus
Inferior oblique
Inferior oblique

17. Accessory Organs of the Eye
Eyebrows
Eyelids and eyelashes
Lacrimal apparatus

18. Thank
you