Complex sentence: In terms of the empirical theory of vision, these perceptual effects arise because in the past, shadowed objects would have emitted less light can all be explained in terms of experience but are difficult to account for in any other way.
Split into simpler sentences: In terms of the empirical theory of vision, these perceptual effects arise because in the past, shadowed objects would have emitted less light. These kinds of effects can all be explained in terms of experience but are difficult to account for in any other way.