Not my tutorial but one I found that is very informative for how to make a night vision effect using photoshop.
http://www.123rf.com/blog/blog.php?idblog=b1000144
http://www.123rf.com/blog/blog.php?idblog=b1000144
Or you could sit something translucent and green in front of the lens.
how would that work with the focusing?...would the cross hairs be blurred if you were focused on figures?