Retina
The retina is located at the back of the human eye.
It can be described as the surface or 'screen' onto which an image is formed by light that has passed into the eye via the cornea, aqueous humour, pupil, lens, vitreous humour then finally the hyaloid membrane before reaching the retina.
The function of the retina is not just to be the screen onto which an image may be formed (necessary but not sufficient), but also to collect the information contained in that image and transmit it to the brain in a suitable form for use by the body.
The retina is therefore a light-sensitive structure lining the interior of the eye. It contains photosensitive cells called rods and cones and their associated nerve fibres that convert the light they detect into nerve impulses that are then sent onto the brain along the optic nerve.
The retina has a complex structure that specialist texts describe in terms of ten layers labelled (from contact with the vitreous humour, outwards towards the back of the eyeball) as:
- Membrana limitans interna.
- Layer of nerve-fibers (stratum opticum).
- Ganglionic layer, consisting of nerve cells.
- Inner molecular, or plexiform, layer.
- Inner nuclear layer, or layer of inner granules.
- Outer molecular, or plexiform, layer.
- Outer nuclear layer, or layer of outer granules.
- Membrana limitans externa.
- Jacob's membrane (layer of rods and cones).
- Pigmentary layer (tapetum nigrum).
More about Ophthalmology:
This section includes short definitions and descriptions of the parts of the eye.
For other descriptions in this category, choose from the list
to the left (but note that this is not a complete / exhaustive list).
Other related sections include:
- A labelled diagram of the eye
- A concise description of the human retina with brief descriptions of the parts of the retina
- Diseases and disorders of the human eye and the human visual system
- Clinical and surgical procedures re. eyes and human visual system
For further information see also our pages of books about ophthalmology.
