Being able to see just about everything is essential to stopping crime, and whether its extrenally or internally, Batman can basically do just that.
Both in his utility belt and in his cowl, Batman has an assortment of viewing options. From the obvious night vision, to heat-tracking, and in some cases an x-ray device. In The Dark Knight, he used a special echolocation device to map out the entire city so he could find the Joker.
Barely anything escapes the Batman when he's looking for them.