In the current light system the spot lights simply appear and others disappear within a specify radius.
The current:
http://www.youtube.com/watch?v=Z_853j8rHsg

I suggest the feature which change the intensity of the light(or alpha layer) when it is appear or disappear. When the light is close enough to show it first it will not visible. As i go closer to it it will start brightening(through x meters). This will show and hide spot lights much smoother way then the current system.