The mage can perceive 360 degrees around himself. He essentially has “eyes” on the back and sides of his head.
The spell extends the mage’s vision around him. As long as he can see (i.e., the area isn’t dark), he can perceive in 360 degrees with a reflexive Wits + Composure roll. It is almost impossible to surprise the mage by sneaking up from behind (a person would need to be well camouflaged, and the mage might need to be heavily distracted by something in another direction).
Free Council Rote: Spatial Topography
Some Free Council willworkers like to think of this rote as an updated version of Zen archery or similar styles of combat, wherein the master is instinctually aware of his surroundings. Adamantine Arrow mages use this very rote for martial purposes.