1. Eye Anatomy & Physiology Conjunctiva & Sclera By : Dr Mohamed Salah Tuesday, 03 July 2018

2. Anatomy of the Eye A.Bony Orbit B.Eye Ball (Globe) Outer layer Middle layer Inner layer Others Muscles Nerves Vessels C.Appendages Lids & Conjunctiva Lacrimal system

3. The Globe Layers Sclera Choroid Retina

4. The Globe Layers LayerComposed of OuterCornea Limbus Sclera MiddleIris Ciliary Muscle Ciliary Body Choroid Inner--- Retina 3 1 2 Uveal Tract 1 2 3 1 2 2 2

5. Sclera  Opaque (light cant pass through)  Posterior five-sixths 5/6 of the globe  Protective coat (hard non-elastic)  Anterior portion is visible (white of the eye) In children sclera is thin - appears bluish (underlying pigmented structures are visible through it) In old age it may become yellowish (deposition of fat) Through the sclera passes : Nerves Blood vessels penetrating into the interior of the eye.

6. Sclera Lamina Cribrosa most posterior portion sclera becomes thin & fenestrated (full of holes) Retinal fibers leave the eye to form the optic nerve Episcleral Tissue loose connective & elastic tissue covers the sclera unites it with the conjunctiva above Sclera = relatively Avascular Episcleral tissue = highly vascular

7. Sclera Attached to extraocular muscles

8. Sclera Functions 1.Protection (Tough) 2.Light Obstruction (Opaque) 3.Muscle Insertion

9. Conjunctiva Translucent, thin mucus membrane Lines the inside of the eyelids (upper & lower) Covers the anterior sclera (the white of the eye) Highly vascularized Palpebral (tarsal) conjunctiva Lines the eyelids Bulbar (ocular) conjunctiva Covers the anterior sclera Stops at the Limbus Does not cover the cornea Fornix conjunctiva Forms the junction between the bulbar and palpebral conjunctivas

10. Conjunctiva Functions : 1.Secrete part of the tear film o Keep the front surface of the eye moist and lubricated o Keep the inner surface of the eyelids moist and lubricated 2.Protect the eye from dust, debris and infection-causing microorganisms

11. Terminology 1.Orbit 2.Conjunctiva 3.Sclera 4.Limbus 5.Opaque 6.Transparent 7.Translucent 8.Anterior 9.Posterior 10.Interior 11.Exterior 12.lamina cribrosa 13.Episcleral Tissue 14.Avascular 15.Extraocular Muscles 16.Palpebral (tarsal) conjunctiva 17.Bulbar (ocular) conjunctiva 18.Fornix conjunctiva