Imperial probe droid was able to detect heat coming from Wampa hiding under snow, which means it was equipped with some kind of IR camera. On the other hand, stormtrooper helmets do not seem to be equipped by any special sensors - or any sensors at all - stormtroopers on Ednor did not notice hundreds of Ewoks hiding nearby before they were attacked, and...
*bonk*
Also, troopers in ANH needed bulky equipment carried in to scan vessel.
On the other hand, Vader's helmed does seem to have some kind of vision augmentation.
But that again proves nothing - there is no indication that such technology is widespread. Instead, stormtrooper's helmets seem to have just ordinary "skiing glasses" - type eye covering built in, along with complete protection for head. Aside from fact that it is probably not easy to break, it is polarized to minimize glare (EIII novelization, and clone trooper armor is basis for stormtrooper one) which is important for aiming in desert environments like Tatooine - althought stormtrooper aim was just terrible. Certainly not useless - but certainly not any kind of sensor either.
Also, we do see some sensor tech (ANH novelization, where imperials carry in sensors to scan inside of Millenium Falcon), but it is, as mentioned in novelization, bulky and unwieldy.
