Making A Seeing Ai

Hey, this should answer many of my questions, i currently have ai set up that depending on what direction its facing it will send out objects which are basically its vision. This works, but not that well, the constant ai object creates lag and having so many enemies means i have to set it up again and again and its just a pain. Also its not that accurate since as you get further away from the enemies the objects spread out more therefore making it inaccurate. Is there any solution other than this? i want it to have vision that stops when it hits a wall?
Thanks Lucas

Here is a simple sensor approach. It doesn't take into account the direction of the enemy, but you should be able to add some conditions/eventing to make that work: Attachment 14283

Thanks A Lot