uncommon divination wizard 

Cast [>] somatic

Range 500 feet

Duration 1 hour

You create an invisible eye sensor, as clairvoyance.

When created, this eye must be in your line of sight. When the spell's duration ends, you can spend 1 Focus Point as a free action to extend the duration for another hour, though as normal, it ends immediately during your next daily preparations.

Core Rulebook, page 407.