DERIVED STRUCTURES FROM EMBRYONIC LAYERS OF THE EYE

1. Surface ectoderm

•  The crystalline lens
•  Epithelium of the cornea
•  Epithelium of the conjunctiva
•  Lacri

lacrimal apparatus and Conjunctiva introduction

What is Conjunctiva
Conjunctiva develops from the ectoderm lining the lids and covering the globe .
Conjunctival glands develop as growth of the basal cells of upper conjunctival fornix. Fewer glands
develop from the lower fornix.

The lacrimal apparatus
Lacrimal gland is formed from about 8 cuneiform epithelial buds which grow by the end of 2nd month
of fetal life from the superolateral side of the
conjunctival sac .
Lacrimal sac,

iris eye , vitreous eye , eyelid anatomy

Iris

• Both layers of epithelium are derived from
  the marginal region of optic cup (neuroectodermal)
• Sphincter and dilator pupillae muscles are
  derived from the anterior epithelium (neuroectodermal).
• Stroma and blood vessels of the iris develop
  from the vascular mesenchyme present anterior
  to the optic cup.

Vitreous
1. Primary or primitive vitreous is mesenchymal in
origin and is a vascular structure having the
hyaloid system of vessels...

what is Cornea , Sclera , Choroid , Ciliary body

Cornea
1. Epithelium is formed from the surface ectoderm.
2. Other layers viz. endothelium, Descemet's..

The Crystalline lens

The crystalline lens is developed from the surface
ectoderm as below :
                                     
Primary lens fibres. The cells of posterior wall of lens vesicle elongate rapidly to form the primary lens
fibres which obliterate the cavity of lens vesicle. The primary..

what is optic nerve

It develops in the framework of optic stalk as
below:

• The neuroectodermal cells forming the walls of optic stalk develop into glial system of the nerve.
• Fibres from the nerve fibre layer of retina grow into optic stalk by passing through the choroidal fissure and form the optic nerve fibres.
• The fibrous septa of the optic nerve are developed from the vascular layer of mesenchyme which invades the nerve at 3rd fetal month.
• Sheaths of optic nerve are formed from the layers of mesenchyme like meninges of other parts of central nervous system.
• Myelination of nerve fibres takes place from brain distally and reaches the lamina cribrosa just before birth and stops there. In some cases, this extends up to around the optic disc and presentsas congenital opaque nerve fibres. These develop after birth.
  
  

Retina structure

Retina is developed from the two walls of the optic cup, namely: (a) nervous retina from the inner wall, and (b) pigment epithelium from the outer wall
.
 
(a) Nervous retina. The inner wall of the