Superb pictures, Gunn! So superb, in fact, that I was motivated to go looking for information... (Dear Google, find me what you can about
"jumping spiders" eyes anatomy.)
I learned that the eyes of a jumping spider are dramatically different from the eyes of other small arthropods. Here are a few references that I found particularly enlightening (pun intended

).
http://www.tolweb.org/accessory/Jumping ... cc_id=1946. "<diagram> Note that the AME's [Anterior Median Eyes] are long and tubular, which helps their resolution (longer focal length, more magnification) but which means they have a narrow field of view. Since the AME's have a narrow field of view, the spider needs to point them in different directions to see different things. To some extent this is done by moving the carapace, but the eyes can move as well. This is not done by moving the whole 'eyeball', since the lenses of the eyes are actually built into the carapace. Instead the retina moves around, while the lens stays fixed. This retinal movement is accomplished by some small muscles: <diagram>"
http://www.boston.com/globe/search/stor ... 062998.htm "They have excellent resolution and can judge distance by comparing the difference in the image produced by each eye."
http://www.absoluteastronomy.com/topics/Jumping_spider "Jumping spiders have very good vision centered in their anterior median eyes (AME). These eyes are able to create a focused image on the retina, which has four layers of receptor cells in it. Physiological experiments have shown that they may have up to four different kinds of receptor cell, with different absorption spectra, giving them the possibility of up to tetrachromatic color vision, with sensitivity extending into the ultra-violet range. Color discrimination has been demonstrated in behavioral experiments."
Pretty cool, eh? An image-forming lens in front of a multicellular retina, with muscular steering and stereo vision. Now
that's an eye!
--Rik
Edit: to repair broken link