Sensory - Vision Development

From Embryology


Historic retina drawing.jpg

These notes introduce the development of the eye: induction and regional specification of the eye structures, maturation and formation of retina and optic tectum neuronal connections. The adult eye has contributions from several different embryonic layers eventually forming neuronal, supportive connective tissue, optical structures, and muscular tissues. Additional pages are being developed to cover specific issues of this anatomical structure.

Vision Links: vision | lens | retina | placode | extraocular muscle | cornea | eyelid | lacrima gland | vision abnormalities | Student project 1 | Student project 2 | Category:Vision | sensory
Historic Embryology - Vision 
Historic Embryology: 1906 Eye Embryology | 1907 Development Atlas | 1912 Eye Development | 1912 Nasolacrimal Duct | 1917 Extraocular Muscle | 1918 Grays Anatomy | 1921 Eye Development | 1922 Optic Primordia | 1925 Eyeball and optic nerve | 1925 Iris | 1927 Oculomotor | 1928 Human Retina | 1928 Retina | 1928 Hyaloid Canal | Historic Disclaimer
Senses Links: Introduction | placode | Hearing and Balance hearing | balance | vision | smell | taste | touch | Stage 22 | Category:Sensory

Some Recent Findings

Adult Human Retina histology[1]
  • Activation of c-Jun N-Terminal Kinase (JNK) during Mitosis in Retinal Progenitor Cells[2] "Most studies of c-Jun N-terminal Kinase (JNK) activation in retinal tissue were done in the context of neurodegeneration. In this study, we investigated the behavior of JNK during mitosis of progenitor cells in the retina of newborn rats. ... The data show, for the first time, that JNK is activated in mitotic progenitor cells of developing retinal tissue, suggesting a new role of JNK in the control of progenitor cell proliferation in the retina."
  • Rearrangement of retinogeniculate projection patterns after eye-specific segregation in mice[3] "When monocular enucleation was performed after eye-specific segregation, rearrangement of retinogeniculate axons in the dorsal lateral geniculate nucleus (dLGN) was observed within 5 days. ...We also examined the critical period for this rearrangement and found that the rearrangement became almost absent by the beginning of the critical period for ocular dominance plasticity in the primary visual cortex."
  • The long noncoding RNA RNCR2 directs mouse retinal cell specification[4]"We find that the RNCR2 is selectively expressed in a subset of both mitotic progenitors and postmitotic retinal precursor cells. ShRNA-mediated knockdown of RNCR2 results in an increase of both amacrine cells and Müller glia, indicating a role for this lncRNA in regulating retinal cell fate specification."


Embryonic Development

  • Weeks 3 - 4 Eye Fields-Optic Vesicle
  • Weeks 5 - 6 Optic Cup, Lens Vesicle, Choroid Fissure, Hyaloid Artery
  • Weeks 7 - 8 Cornea, Anterior Chamber, Pupillary Membrane, Lens, Retina
  • Weeks 9 - 15 Iris, Ciliary Body
  • Weeks 8 - 10 Eyelids
Eye and retina cartoon.jpg

Carnegie Stages - Eye

The following data is from a study of human embryonic carnegie stages[5] and other sources.

  • Stage 10 - optic primordia appear.
  • Stage 11 - right and left optic primordia meet at the optic chiasma forming a U-shaped rim.
  • Stage 12 - optic neural crest reaches its maximum extent and the optic vesicle becomes covered by a complete sheath,
  • Stage 13 - By the end of the fourth week the optic vesicle lies close to the surface ectoderm. Optic evagination differentiation allows identification of optic part of retina, future pigmented layer of retina, and optic stalk. The surface ectoderm overlying the optic vesicle, in response to this contact, has thickened to form the lense placode.
  • Stage 14 - (about 32 days) the lens placode is indented by the lens pit, cup-shaped and still communicates with the surface by a narrowing pore.
  • Stage 15 - (about 33 days) the lens pit is closed. The lens vesicle and optic cup lie close to the surface ectoderm and appear to press against the surface.
  • Stage 16 - (37 days) Growth of the lens body results in a D-shaped lens cavity. Perilental blood vessels (tunica vasculosa lentis) are visible. Prior to the development of the eyelids, one small sulcus or groove forms above the eye (eyelid groove) and another below it.
  • Stages 17 - 19 - Retinal pigment is visible and the retinal fissure is largely closed. Eyelids grooves deepen, eyelid folds develop, first below, and then above, the eye.
  • Stages 18 - Mesenchyme invades the region between the lens epithelium and the surface ectoderm.
  • Stages 19 - 22 - the eyelid folds develop into the eyelids and cover more of the eye as the palpebral fissure takes shape. The upper and the lower eyelids meet at the outer canthus in Stage 19.
  • Stage 20 - The lens cavity is lost and a lens suture begins to form. The inner canthus is established.
  • Stage 23 - The retina comprises the pigmented layer, external limiting membrane, proliferative zone, external neuroblastic layer, transient fiber layer, internal neuroblastic layer, nerve fiber layer, and internal limiting membrane. Eyelids closure is complete (Note - shown as still open in the Kyoto embryo).


Human Lens (stage 22)

The lens or crystalline lens or aquula (Latin, aquula = a little stream) has a key role in focussing light (with the cornea) upon the neural retina. The lens embryonic origin is from surface ectoderm of the sensory placodes that form in the head region (More? Week 4 - Placodes). The lens focusses by refracting light as it passes through the biconvex lens, which can be altered in shape (accommodation) by surrounding ciliary muscles. These ciliary muscles are activated (contracted) by parasympathetic innervation from the ciliary ganglion itself innervated by the oculomotor nerve (Cranial Nerve III) (More? Cranial Nerves).

surface ectoderm -> lens placode -> lens pit -> lens vesicle -> lens fibres -> lens capsule and embryonic/fetal nucleus.

Retinotopic Map

This neuroscience term describes how the developing retina is precisely "mapped" onto the visual cortex through a series of signaling and activity dependent mechanisms. This follows from Hubel and Wiesel (1981 Nobel Prize in Physiology or Medicine) key discoveries (1959-70) of how in development system matching occurs in the visual system. The topographic map establishes an ordered neuronal connection between sensory structures and the central nervous system.

The retinotectal map (eye to brain) of birds (lower vertebrates):

  • temporal (posterior) retina is connected to the rostral (anterior) part of the contralateral optic tectum
  • nasal (anterior) retina to the caudal (posterior) tectum
  • ventral retina to the dorsal (medial) tectum
  • dorsal ventral (lateral) tectum

Retinal waves a form of coordinated spontaneous activity that occurs in the developing retina. These waves of electrical activity (action potentials) are thought to have a role in establishing the initial retinotopic map by correlating/coordinating the activity of neighbouring retinal ganglion cells.

EphA/ephrin-A molecular signaling also thought to have a role in establishing the initial retinotopic map.

Neural Crest

Mouse eye neural crest.jpg

Mouse eye neural crest[6]

Mouse eye TGF-beta model.jpg

Mouse eye TGF-beta model[6]

Links: Image - Mouse eye neural crest | Image - Mouse eye TGF-beta model | Vision Development | Neural Crest Development | Head Development

Extraocular Muscles

Human extraocular muscles 01.jpg

Additional Images

Historic Images


  1. <pubmed>12186651</pubmed>| Genome Biol.
  2. <pubmed>22496813</pubmed>
  3. <pubmed>20544023</pubmed>| PLoS ONE
  4. <pubmed>20459797</pubmed>
  5. <pubmed>7364662</pubmed>
  6. 6.0 6.1 <pubmed>16403239</pubmed>| J Biol.

Online Textbooks


<pubmed>20855501</pubmed>| JCB

The International Journal of Developmental Biology Vol. 48 Nos. 8/9 (2004) Eye Development



Bookshelf vision development

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  • retina - The stratified sensory structure of the eye, formed from the neural ectoderm that extends from the forebrain (diencephalon) to form initially the folded optic cup. Vertebrates have ten identifiable layers formed from nerve fibers, neurons, membranes, photoreceptors and pigmented cells. Light must pass through nearly all these layers to the photoreceptors. (1. Inner limiting membrane - Müller cell footplates; 2. Nerve fiber layer; 3. Ganglion cell layer - layer of retinal ganglion cells their axons form the nerve fiber layer and eventually the optic nerve; 4. Inner plexiform layer - another layer of neuronal processes; 5. Inner nuclear layer; 6. Outer plexiform layer; 7. Outer nuclear layer; 8. External limiting membrane - layer separating inner segment portions of photoreceptors from their cell nuclei; 9. Photoreceptor layer - rods and cones that convert light into signals; 10. Retinal pigment epithelium).
  • retinal pigment epithelium - (RPE) An epethial pigmented cell layer lying outside the sensory retina, formed from the outer layer of the folded optic cup. The RPE is firmly attached to the underlying choroid and overlying retinal visual cells, for which it has a nutritional role.
  • retinal waves - A form of coordinated spontaneous activity that occurs in the developing retina. These waves of electrical activity (action potentials) along with EphA/ephrin-A signaling are thought to have a role in establishing the initial retinotopic map by correlating/coordinating the activity of neighbouring retinal ganglion cells.

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Cite this page: Hill, M.A. (2020, October 21) Embryology Sensory - Vision Development. Retrieved from

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