A really homogeneous area offering nothing to be cannot be given to any perception. The structure of actual perception alone 
can teach us what perception is. The pure impression is, therefore, not only undiscoverable, but also imperceptible 
and so inconceivable as an instant of perception. If it is introduced, it is because instead of attending to 
the experience of perception, we overlook it in favour of the object perceived. A visual field is not made up of limited views. But an object seen is made up of bits of matter, and spatial points are external to each other. An isolated datum of perception is inconceivable, at least if we do the mental experiment of attempting to perceive such a thing. 
But in the world there are either isolated objects or a physical void.

Phenomenology of Perception
Merleau-Ponty