Outer Nuclear Layer

The Outer Nuclear Layer is the seventh (7th) of the layers forming the retina of the human eye.

Recall that light from outside the human body enters the eye through its main structures of the cornea, aqueous humour, pupil, lens, etc. and is normally focussed onto the retina of the eye.

The retina is composed of several layers which, together, form the "screen" in the eye onto which an image of the area viewed by the eye is formed, and information about that image is segmented into packets of information that are passed to the visual cortex of the brain via the optic nerve.

The outer nuclear layer is similar to the inner nuclear layer in that both contain several sub-layers of oval-shaped components.

In the case of the outer nuclear layer there are two types of cells. These are called rod-granules and cone-granules, and are connected with the rods and cones, respectively.

The rod-granules are the most numerous the the two types.
These are located at various different levels within the outer nuclear layer of the retina. Fine processes extend from two opposite sides of each rod-granule. The "outer-process" which extends towards the back of the retina is aligned with a single rod in Jacob's Membrane (layer 9) of the retina. The "inner-process" traverses towards the outer molecular layer (layer 6) of the retina where it terminates at a point of connection with the "outer-process" of a rod-bipolar.
The cone-granules are located close the membrana limitans externa, through which each one is located in alignment with a single cone in Jacob's Membrane (layer 9).
Each cone-granule contains a pear-shaped ("pyriform") nucleus that almost completely fills the cell and is connected, via a thick process that terminates in multiple thin fibrils, with the outer process of a cone-bipolar in the outer molecular layer (layer 6).

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Outer Nuclear Layer

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