The development of the human eye begins around 22 days when the embryo is about 2 mm long. The main components that form the eyeball are the optic vesicle, lens placode, and surrounding mesoderm. By the end of the fourth week, the optic vesicle bulges out to form the optic cup, with the proximal part forming the optic stalk. The surface ectoderm thickens over the optic vesicle to form the lens placode which then sinks below the surface to form the lens vesicle. Associated mesenchyme condenses and differentiates to form layers that will develop into structures like the cornea, sclera, iris, choroid and ciliary body.

1. Embryology of human eye
(part 1)
 Presentation by
 Saroj sah
 Rama university
 Kanpur,UP

2. Embryology of human eye (part 1)
 The development of eyeball can be considered to
commence around (22 day) when the embro has
eight pairs of somites and around ( 2 mm ) in length.
 On day 22 development of eye begins
 Components of eyeball are derived form :-
 A) Optic vesicle :- Outgrouth form prosencephalon
 B) Lens placode :- Specialized area of surface
ectoderm.
 C) Mesoderm :- Surrounding optic vesicle.

3. At about end of fourth week, three primary
brain vesicle are formed

4. Formation of Optic vesicle and optic stalk
 The area of neural plate that form prosencephalon
which show thickened area on each side that become
depressed to form optic sulcus.
 Then neural plate gets convert into prosencephalic
vessicle.
 Optic sulcus bulges outward to form optic vesicle.
 The proximal part of optic vesicle becomes
constricted and elongated to form optic stalk.

7. Formation of lens vesicle
 The optic vesicle grows laterally and comes in
contact with surface ectoderm.
 Then surface ectoderm,overlying the optic vesicle
that becomes thickened to form lens placode,that
sink below the surface to convert lens vesicle.
 Also it soon separated from surface ectoderm at 33rd
day of gestation.

9. Formation of Optic cup
 The optic cup is converted into a double layer optic
cup.
 It is due to developing lens in invaginated itself into
the optic vesicle.
 In fact conversion of the optic vesicle to the optic cup
is due to differential growth of the walls of the
vesicle.
 The margins of optic cup grow over the upper and
lateral sides of the lens to close it.

10.  So growth does not take place over the inferior part
of the lens that is why the walls of the cup show
deficiency in this part.
 This deficiency extends to some distance along the
inferior surface of the optic stalk and is called
Choroidal or fetal fissure.

12. Changes in the associated mesenchyme
 The developing neural tube ( from which central
nervous system develops) is surrounded by
mesenchyme, which subsequently condenses to
form menings.
 An extension of this mesenchyme also covers the
optic vessels
 Later, this mesenchyme differenciates to form a
superficial fibrous layer (corresponding toDura) and
deeper vascular layer ( corresponding to Pia-
arachnoid).

14. Fibrous layer of mesenchyme
 It forms
 1) corneal stroma in the anterior parts.
 2) sclera and extraocular muscles in the
posterior patrs.
 VASCULAR LAYER OF MESENCHYME :-
 1) Hyaloid system of vessels :- with the
formation of optic cup, part of inner vascular layer of
mesenchyme is carried into cp through choroidal
fissure

15.  2) Iidopupillary membrane :-
 It is formed from anterior part of vascular layer of
mesenchyme.
 In the peripheral region , it is attached to the
anterior part of the optic cup to form the iris.
 Then, the central part of this lamina is pupillary
membrane which also form tunica vasculosa lentis.
 3) Choroid and ciliary body :-
 They are formed from the posterior parts of the
vascular layer of mesenchyme.

17.  If you don’t know my slide then please visit to my
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18.  THANK YOU