*-axis.png
==========
the following icons come from the mayavi and related packages:
/usr/lib64/python2.7/site-packages/enthought/tvtk/pyface/images/16x16/x-axis.png
/usr/lib64/python2.7/site-packages/enthought/tvtk/pyface/images/16x16/y-axis.png
/usr/lib64/python2.7/site-packages/enthought/tvtk/pyface/images/16x16/z-axis.png

License: BSD

3d_glasses.png
==============
http://www.softicons.com/free-icons/toolbar-icons/fatcow-hosting-icons-by-fatcow/3d-glasses-icon

License: CC Attribution 3.0 United States

stock-eye-20*.png
================
taken/based on the GIMP icons in
/usr/share/gtk-doc/html/libgimpwidgets/

License: GPL-3
