And so, my robot eye fantasies continue. A paper caught my eye today, whilst shuffling my mess from oneend of the room to the other. Le Scribe Accropi! The first schematic eye ever. Ancient Egyptian statue. Copper "retina", so to speak. Painted iris. Lens, so that, possibly, when tomb raiders torchlight flashed off the back of the retina, they would leave in a fright, and leave the pharaoh to his treasure (sp[eculation, of course!).
Jay Enoch is the researcher. He has been involved in vision research since the 50s and 60s I think. Last I checked, still a prof in California somewhere. I am surprised that few people seem to know the history of lens design, as laid out by Rudolf Kingslake in his book of the same name. The Petzval (Coddington) curvature was significant obstacle to the proper development of the photographic lens, and took about a decade or two to properly fix. It seems to have been forgotten, that we have developed methods to flatten the field. Now that we have a suitable photosensitive surface, even capable of a rough sort of 3-D shape--if one tries hard enough--nobody seems willing to re-un-design it!
And what of the fundamental knowledge of Ptolemy, al Hazen, and subsequently, Snell? Why would we (modern day researchers) ignore what is known about optical materials, namely, low refractive index materials? The human cornea, lens, and aqeuous and vitreous humors, have relatively low refractive idices, compared to most optical glasses. The plastics are a bit closer, but, truly, one must gravitate towards optical crystals in order to mimic the natural materials. Unfortunately, those crystal materials are either harder to work, or exhibit some sort of objectionable, nonlinear properties (birefringence, polarization, etc.).
One of my lens design books has a paper model, with some ray tracing through the human eye. But I can only find one reference to anybody who has EVER tried (besides the sculptural attempt of the Ancient Egyptians) to construct a working, 1:1 scale model of the optics of the human eye (well, actually, his was more like 1.5;1; a smidgen bigger. G.H. Gliddon circa 1927; Dartmouth). As for "silicon retinas", under Carver Mead and the neuromorphic research programs, several researchers have attempted some implementations. T. Delbruck, for one, Misha Mahowald, another (I just stumbled across the title of her book, and am kicking myself for not obtaining a copy from somewhere! "An Analog VLSI System for Stereoscopic Vision".). Boahen is another who goes the Neuromorphic route. While I do not favor "chips that act like neurons" as an optimal research strategy, I should mention that I see its appeal, as does that DARPA guy (Robert Colwell), whose you tube talk
https://www.youtube.com/watch?v=JpgV6rCn5-g I've referenced on another thread.
Other "retina-like chips" include the first, van der Speigel et. al., circa 1989, wodnicki et. al, and sandini et. al. There are many more, and I have only scratched the surface. I know enough to know, that if the device I am thinking of exists, it sure is hard to find.
So, on the "biology" side of things, I could mention Ramon y Cajal, winner of the Nobel Prize, and his fine microscopy and artwork of the retina (and his evidence supporting neuron theory!). Osterberg, the first to estimate the number of retinal cells, bears mentioning, though the numbers (circa 1990s) are a bit reduced by modern statistical sampling (Curcio et. al). Also, Gullstarnd, another Nobel Prize winner, should be mentioned, as well as Polyak, the U. of CHicgao prof. who wrote several large, seminal tomes on the vertebrate and human eye.
The modern textbooks that bear mentioning are probably, Clyde Oysters "Human Eye; its structure and function" and Smith and Atchison's work on the dipotrics of the human eye. Any person who winds his way through these works and then proceeds to tell me "why make a robot eye. its impossible. its already been done. we already know everything about the human eye.", is just showing their ignorance.
Other fine works that bear mentioning are Nicholas Wade's "Natural history of vision" and David Parks "Fire in the eye". And just two summers ago, I got a chance to go to the national archives and view the Harvard optical Laboratory papers on "Optical Fluorite for Aerial Lenses". Quite a journey for me, and not something I take lightly. One hopes my fluorite doesn't crack, when I start working it. Thermal stress is easily generated and the crystal doesn't hold up to well. Also, its tough to polish (so I've been told).
Still have much design work to do, on my student "OSLO" CAD program. I'll get this lens thingy made!
Well, that's it for tonight.