Direct Perception

Direct perception, also known as Direct Realism, or Naive Realism, (or Epistemological Monism) is the natural intuitive understanding of vision that we accept without question from the earliest days of childhood, i.e. that the world we see around us is the world itself.

Indirect Perception

Indirect Perception, also known as Indirect Realism or Representationalism, (or Epistemological Dualism) suggests on the other hand that the world we see around us is not the real world itself, but merely a perceptual replica of that world.

Projection Theory (and other half-way theories)

There is a third alternative, which is a Projection Theory, (and other half-way theories) whereby perception is indeed an internal representation in the brain, but the subjective experience of that representation is somehow projected back out of the brain to be superimposed on the world itself.