not really, you would need it to be exposed to lua but you can modify the ai script yourself as a temporary fix
in module_combatcore.lua you will find the 'detectplayer' function
function module_combatcore.detectplayer(e,AIObjNo,PlayerDist,CanFire,detectstate)
where you could add some modification to the check
if (PlayerDist < AIGetEntityViewRange(AIObjNo)
like
if (PlayerDist < AIGetEntityViewRange(AIObjNo) * visibility[e]
so if you set visibility[e] to 1 the AI has full view range but 0.5 is half view range etc
note; due to the ai having a lot of behaviors and other areas that check for the player it may not always works as expected