Im sorry to bother every one with my question that will make me sound like and idiot, but i just have to know. What is the circle in the head light? and what is purpose. I can tell its some kind of intake but what for? a turbo? if any body can help me out it wold be greatley appreciated.  


http://www.bestofebay.net/wp-content/images/supra_43_std.jpg


http://optikaituning.com/images/nissan_skyline_gtr.jpg  

Air intake duct going into the air box or turbo(s)