When a beam of light meet the boundary between two different media,


The same laws applied when light wave impinging the surface of a lens.
This java applet let you play with a thick lens.



How to play:





Approximate indices of refraction of various substance
Air1.00029
ice1.31
water1.333
Ethyl alcohol1.36
Fused quartz SiO21.4584
glass1.5 - 1.6
diamond2.417
Futile TiO22.907
Gallium phosphide3.50



http://www.youtube.com/watch?v=EXmaY2txEBo