Adaptive Optics – Amazing image resolution from live human eyes
I'm just back from the European Optical Society Meeting on Visual and Physiological Optics in Dublin, well organised by Brian and team. Optics is not my field, but luckily I was invited to give the opening keynote, so I learned more about their exciting advances. Boy, have they come a long way in the last 10–15 years! The picture below is slightly rearranged from Steven Burns' website http://www.opt.indiana.edu/people/faculty/burns/CenterForOphthalmicImaging/AOSLO.htm. The left two images are adaptive optics off (1b, already good) and on (1c). An obvious improvement; the little bright dots are cones from a living human eyes, their diameter is a little over 1 µm. Interestingly, it's currently unclear why they come in different shades of grey. 1d) shows again cones, the dark bands being blood vessels; imaging a little less distant 1e) shows the nerve fibre layer (these bundles arcing from top left to bottom right) and, again, the blood vessels.
In addition to imaging, you can also stimulate the cones to that precision: Wolf Harmening, currently in Austin Roorda's lab, presented on “single-cone psychophysics”. There was much more, of course…
I find this exciting, first for its advances in basic research but also beacuse it will doubtless lead to fruitful clinical applications.