Direct realism is the theory of perception that results from a belief in "presentism", or Alexandrian Cosmology (Whitehead 1920). 

This can be seen in the analysis of statements such as "According to DR, the experience is a relation between the perceiving subject and the cat", the idea that perception is "pseudodynamic" and the explanation of our experience containing whole words and bars of tunes as narratives about words and tunes.  In all these cases it is implied that experience has a temporal component such as the pointing action required in a "relationship", the dynamism of "pseudodynamic" and the obvious time extension of a tune in our experience. However, if the existence of time is rejected it is impossible to have a four dimensional form that truly models the relationship or the pseudodynamic structure or the bar of a tune.

In the absence of the possibility of four dimensional forms the presentist is doomed to invent an account of perception that is little more than a catalogue of the sequence of instantaneous events that taken together might sit under the label perception.  Perception becomes the tree, the processing of the information about the tree and the response to the tree with no room for any internal perceptual experience.  If you do not believe that time exists you have no other choice, you cannot propose that there might be four dimensional objects in the brain that model the tree in experience, including its dynamic relationships. When the presentist listens to music they must deny that they hear more than a semi-quaver at the position of the instrument in their experience and instead describe the music as a narrative - though how they hear the narrative is a mystery - perhaps by using another narrative? When the presentist looks in a mirror and sees stable eyes no matter how their gaze flits from place to place they can only say it is all an illusion.

Whitehead(1920) spotted this link between presentism and philosophy and pointed out that spacetime has an entirely different geometry from a stack of 3D spaces but he also noted that conventional ideas were deeply embedded. Indeed they are so embedded that reality can seem like heresy.