The Force Lightning skill, plus most if not all the other lightning abilities that use that particle effect, do not show up properly on AMD/ATi video cards. As of right now, this bug is still in effect. Its been around since beta, and has been reported already. Nothing has been done about it.
http://imageshack.us/a/img441/6258/forcelightning.jpg
Uploaded with ImageShack.us
I want to hear something from bioware that this is going to get fixed.