1. Anatomy and Embryology of the Eye
Julie D Barliana
Pediatri-Ophthalmology Division
Ophthalmology Department FMUI/RSCM

2. The Protective Structures of the Eye
O TheOrbit
o The Lids
o The Sclera
The Anterior Segment of the Eye
o The Cornea
o The Aqueous Humor
o The Iris
o The CrystallineLens and CiliaryMuscle
The Posterior Segment of the Eye
o The Retina
o The Vitreous Humor
The Visual System Pathways to the Brain
o The Optic Nerves and Optic Tracts
o The Lateral Geniculate Nucleus
o The Visual Cortex

3. Anatomy of the eye
Cornea
Iris
Ciliary body
Lens
vitreus body
Retina
Choroid
Optic nerve (NII)

4. Anatomy of the Eye
Anterior
chamber
(Camera Oculi
Anterior)
Posterior
Chamber (Camera Hyaloid Canal)
Oculi Posterior)
Badan Kaca
(vitreus body)
Central Vessel Retina

5. Embryo

6. Eye Development
I. Eye Fields-Optic Vesicle
(Weeks 3-4)
II. Optic Cup, Lens Vesicle,
Choroid Fissure, Hyaloid
Artery (Weeks 5-6)
III. Cornea, Anterior Chamber,
Pupillary Membrane, Lens,
Retina (Weeks 7-8)
IV. Iris, Ciliary Body
(Weeks 9-15)
V. Eyelids (Weeks 8-10)

7. A cut through the embryo demonstrates the
relationship of the optic groove to this
ectoderm.
the neuroectoderm of the optic groove comes
into close contact with the surface ectoderm
in the area indicated

8. Optic Vesicle
(Weeks 3-4)
The line indicates the
location of the cut. The optic grooves
form the optic stalks Contact between the neural
and the optic ectoderm of the optic vesicle and
vesicles. the surface ectoderm results in
induction of the lens placode.

9. Cutting the embryo in the indicated plane
illustrates the lens placode and the adjacent
portion of the optic vesicle as it begins to
invaginate

10. Optic Cup, Lens Vesicle,
Choroid Fissure, Hyaloid Artery (Weeks 5-6)
The invaginating lens placode forms the lens
vesicle that pinches off the surface ectoderm.
Invagination of the optic vesicle forms the
bilayered optic cup that remains connected to
the forebrain via the optic stalk.

11. Contact between the The lens placode The lens vesicle eventually
surface ectoderm and invaginates, forming the becomes the lens and the two
the budding optic lens vesicle. layers of the optic cup become
vesicle induces the Concurrently, the optic the neural and pigmented layers
differentiation of a vesicle becomes the of the retina.
population of cells optic cup.
that will form the lens
placode.

12. This diagram represents
the cut shown by the
dotted line. The hyaloid
artery courses through
the choroid fissure.
The optic vesicle and the
optic stalk invaginate,
illustrates the lens vesicle
forming the choroid fissure
and the hyaloid artery.
inferiorly.
The arrows show the areas of
invagination.

13. Cornea, Anterior Chamber,
Pupillary Membrane,
Lens, Retina (Weeks 7-8)
The hyaloid vasculature surrounds the back of
the lens. Following separation of the lens
from the surface, the posterior lens fibers The anterior chamber of the eye
elongate to obliterate the lens cavity and the forms as a space develops between
cornea begins to differentiate the lens and its closely associated
iridopupillary membrane and the
cornea.

14. Cornea
The cornea consists of an
outer epithelial layer derived
from surface ectoderm and
inner layers derived from
neural crest cells.

15. Iris, Ciliary Body (Weeks 9-15)
The pupillary membrane should regress, but
may persist after birth, appearing as in the
diagram.

16. Retina
As the retina develops, the pigmented layer
becomes relatively thinner while the neural
portion thickens.
As the neural portion develops,
it differentiates into distinct
cell layers.

17. Iris, Ciliary Body (Weeks 9-15)
The iris forms from the outer rim of the optic
cup
Folding of these layers
results in formation of the
ciliary processes.
At the rim of the optic cup, the inner and outer layers
become closely associated.

18. Eyelids (Weeks 8-10)
By the end of the embryonic The eyelids fuse at the beginning of the
period, eyelids begin to form. second trimester and reopen at the beginning
of the third trimester.

19. Iris and Cilliary body

20. Some Ocular Anomalies
Retinal detachment—between inner and outer
portions of the optic cup derivatives
•congenital—failure of fusion
•acquired—trauma
Defects in closure of optic (choroid) fissure
•retinal coloboma
•iridial coloboma
Aniridia — (rare) 1 in 75,000

21. Extraocular Muscles
Develop from somitomeres I-
IV (paraxial mesoderm cranial
to the occipital somites)
Innervated via CN III, IV, & VI
Coordinate movements between the two eyes
(usually conjugate, although some instances
of physiological vergence exist)

22. Extraocular mm.
Inferior oblique
Medial rectus
Superior oblique
Superior rectus
Levator palpebrae sup.
Lateral rectus
Inferior rectus
(not shown)

23. Oculomotor Nerve (CN III)
Somatic motor
Parasympathetic
(oculomotor nucleus):
(Edinger-Westphal nucleus):
Sup. rectus, Inf. rectus,
Ciliary m. &
Med. rectus, Inferior oblique
Constrictor pupillae m.
& Levator palpebrae superior
mm.

24. Trochlear Nerve (CN IV) Abducens Nerve (CN VI)
Somatic motor only Somatic motor only
(trochlear nucleus): (abducens nucleus):
•Superior oblique m. •Lateral rectus m.

25. Extraocular Muscle Anomalies (congenital)
• Agenesis (single muscle usually)
• Anomalous Attachments
– misplaced
– additional attachments
• Adherence & Fibrosis Syndromes
**Failure to align visual axes (strabismus), thus potentially
resulting in diplopia (double-vision)
Amblyopia—reduced/absent visual ability in one eye
“lazy” eye

26. VISUAL REFLEXES
Pupillary Light Reflexes: 30wks gestation
– Constriction (parasympathetic)
– Dilation (sympathetic)
Accommodation (4 months = well developed)
(The Near Reflex)

27. Visual Development

28. Visual Developmental “Milestones”
• Pupillary Light Reaction—30 wks gestation
(CN II/symp/parasymp integration)
• Lid closure in response to bright light—30 wks gest.
(CN II—CN VII reflex)
• Blink response to visual threat—2-5months
(CN II—CN VII reflex)
• Visual Fixation—birth (well dev=6-9wks)
• Visual Following—3 months
• Accommodation—4 months

29. Visual pathway

30. Rods and Cones
• Cone cells see in bright light and rod cells see
in black and white and in dark light

31. Physiology of Vision
• Light energy enters the eye, and the cornea
and lens focus it onto the retina
• The light stimulates the rods and cones, two
types of cells found in retina
• The rods and cones send impulses to the optic
nerve, which carries them to the visual area of
the cortex
• The cortex interprets the image and you “see”

33. • Nearsightedness occurs
when light is focused in
front of the retina
• Farsightedness occurs when
light is focused behind the
retina
• Concave lens, thicker at
edge than in the middle,
corrects nearsightedness
• Convex lens, thicker in
middle than at edge,
corrects farsightedness

34. Visual development
• In the early months of life
– the visual system is still developing
• In a premature infant:
– depending on the extent of prematurity
– the eyelids may not have fully separated; the iris
may not constrict or dilate
– retinal blood vessels may be immature
– visual system is not ready to function

35. At birth:
•the pupils are not yet able to dilate fully
•newborn has poor fixation ability
•limited orienting to single targets from birth to
3 months

36. By 3 months
• ocular movements are coordinated most of the time;
• attraction is to both black and white and coloured
(yellow and red) targets;
• the infant is capable of glancing at smaller targets
(as small as 2.5 cm, or about 1 in.);
• visual attention and visual searching begin;
• the infant begins to associate visual stimuli with an
event (e.g., the bottle and feeding)

37. By 5-6 months
• The infant is able to look at an object in his/her own
hands
• ocular movement, although still uncoordinated at
times, is smoother
• the infant is visually aware of the environment
("explores" visually), and can shift gaze from near to
far easily
• the infant can "study" objects visually at near point
and can converge the eyes to do so; can fixate at 1m
• eye-hand coordination