The problem with percieving Reality is that it is very much dependent on the sensory input of the perciever; with our natural senses we can get thin slices of reality, often conflicting with each other and then construct from that an "inner reality model" that we percieve. This is not only limitation of our senses but also of our physical brain and psychological thought processes.

Using instruments we can get different sizes and shapes of Reality that can be compressed into our sensory input but it still is not the whole Reality-as-is, and we still are limited in the processing side.