2. INTRODUCTION:-
• Eye is the organ of the sense of sight
• Situated in the orbital cavity
• Supplied by the optic nerve (2nd cranial nerve)
• Spherical in shape
3. Layers of the eye:-
• Outer fibrous layer- sclera and cornea
• Middle vascular layer- choroid, ciliary body,
iris.
• Inner nervous tissue layer-retina
4.
5. SCLERA AND CORNEA
• Sclera forms the outermost layer in the
posterior and lateral aspects of the eye ball.
• Sclera is continuous anteriorly with the
transparent cornea.
6.
7. CHOROID
• It lines the posterior five sixths of the inner
surface of the sclera.
• Deep chocolate brown in colour
• Rich in blood vessels
8. CILIARY BODY
• Anterior continuation of the choroid
• Consists ciliary muscles
• Contraction and relaxation of the ciliary
muscle changes the thickness of the lens
• Ciliary body secretes aqueous fluid
9. IRIS
• It is the visible coloured part of the eye.
• Lies behind the cornea infront of the lens.
• Iris is supplied by parasympathetic and
sympathetic nerves
• Parasympathetic stimulation constricts the
pupil and sympathetic stimulation dilates it
• Colour of the iris is genetically determined and
depends on number of pigment cells present
10. LENS
• Lens is a highly elastic , circular biconvex body,
lying immediately behind the pupil.
• It is suspended from the ciliary body by the
suspensory ligament
11. RETINA
• It is the innermost layer of the wall of the eye.
• It is an extremely delicate structure
• Has a layer of sensory receptor cells: rods and
cones
• Rods and cones contain photosensitive
pigments that convert light rays into nerve
impulses.
• Rods are sensitive to dim light & cones are
sensitive to bright light.
12. Blood supply to the
eye
• Arterial supply:- Ciliary arteries and central
retinal artery
• Venous drainage:- central retinal vein.
13. ACCESSORY ORGANS OF THE EYE:-
• Eyebrows
• Eyelids & eyelashes
• Lacrimal apparatus
