http://www.owneye.com.au/
It is expensive to buy it new but it is interesting in its optical properties I think. It is in fact a concave/concave (meniscus?) lens with a mirror backing. Put it up to your eye and you see a
highly magnified, extremely clear, extremely wide angle, view of your eye. If you make a hole in a postcard
and hold it to your eye and look at the mirror you see that it has a very wide angle view with pincushion distortion with flat focus and no color
aberrations. You could make a strange kind of wide angle 3d viewer out of two of them where you looked at
3d pairs of images and you would see your eyes peering around in the middle of the scene
You can see that the back of the mirror is silver, not painted opaque so you could use it also as a high quality
front surface mirror for 360 panoramic photography.
PeterM
