Complex cells are the types of cells that respond most strongly to a stimulus moving perpendicular to its axis.
This is because like simple cell, a complex cell will respond primarily to oriented edges and rating but it has a specific degree of spatial variance. This means its own receptive field cannot be mapped into fixed excitatory and inhiborty zone. Rather, it will respond to patterns of light in a specific orientation within a large field of reception, regardless of its location. Some of these complex cells respond optimally only to a movement in a certain or specific direction.