On the introductory page, I claimed that the ganglion cell layer is a bottleneck.  Let us look at this analogy, see if it is appropriate and, if not, come up with a better one.  A bottleneck is a common analogy to indicate that there is a point where less "stuff" can pass.  In a real bottle, the fluid is held up exiting through the neck of the bottle because it is thinner than the rest of the bottle.  However, a bottleneck literally eventually lets everything through, more slowly perhaps but everything get through in the end.  You might even have some turbulence if there is too much liquid trying to get through.  

Somehow that is not what I am trying to get across.  I think some of the visual pattern of light does not get out of the retina.  Yes, the ganglion cell layer is a bottleneck in that it is thinner, but not everything is allowed through.  Perhaps a sieve is a better analogy.  A sieve, in a general sense, only lets some "stuff" through and not other stuff.  In a real sieve it is that only that part of the flour, or whatever is being sifted, that is small enough to get through will be allowed through.  In applying this analogy, it is not necessary to limit the sifting to size.  We might conceive of a sieve that sifts basing on shape or other characteristics of the material.  So a sieve is different from a bottleneck.  In a sieve, something can get left behind which seems to be more to the point.  It is not a slowing down of information as much as a selection of what gets transmitted.  Moreover, the selection is not random us meaningful and done in a way to get as much through as needed.  If we apply selective pressures to various sieves, then those that let useful information through will give a survival advantage.  

In addition, to the proper analogy for the functioning of the ganglion cell layer, here are some of the background ideas that I am considering in developing this model.  In time I hope to flesh out these ideas and describe and explain them in detail.