As with the rest of the undead physiology, the zombie senses are no more acute than our own. They do tend to make the best of what they have and their lack of pain receptors makes them a difficult enemy in battle.
The eyesight of a zombie is the same as their previous human self, less what decomposition has degraded. How the limited brian function of the zombie interprets the images sent to it by the eyes is not fully understood. They seem to be able to see and identify prey, but it is unclear how they determine the difference between human prey and other walking dead. Some believe that they have better night vision, but it appears this is simply anecdotal based on nighttime attacks. There doesn’t to appear to be any real evidence that a zombie has any sort of extraordinary night vision.
It does appear that the undead have a somewhat better developed sense of smell than their human counterparts. Given that they don’t seem to have any other extraordinary capabilities, it is theorized that they simply rely on their sense of smell more than we humans. They do seem to be able to smell the difference between the dead and the living. This may account for how they can distinguish the living flesh from the undead around them.
The undead are capable of both hearing sounds and determining the direction they are coming from, much like humans. The similarities seem to end there. They are attracted to noise and will move toward it, but do not seem to be able to distinguish between the sounds of inanimate objects and animals or humans. Like smell, some believe their hearing is more acute, but it appears they simply rely it more than humans.
While zombies seem to have a rudimentary sense of touch (a sense that they have ahold of something when they grab it), they have no sensation of pain. This makes them a dangerous enemy. Where inflicting pain on a human in combat might subdue them or even send them into shock, the zombie just keeps coming. You simply can’t inflect enough pain to stop or deter a zombie.
The undead have a rudimentary sense of taste as they can tell between human flesh and that of animals and, given the choice, prefer human flesh. Either through taste, smell, or a combination of both, they can tell if flesh is “fresh enough” for them. They will not eat something that has been dead for more than twelve hours or so.