Eric Lippert is running an eye-catcher series on High Dimensional spaces (see here part one and two). Which got me thinking. The classical laws of Optics work can be easily generqalized to N spatial dimensions. You could easily imagine things like refraction point of a material, lenses, sources of light and so on in a four-dimensional space for example. And also more advanced things like refraction, diffusion, and even the Fresnel effect!
I am sure that there are relevant images on the web, but I can't seem to find them. Any ideas?