Fig. 6. Optokinetic response to split optokinesis in the naso-temporal direction for both eyes, stimulus speed 15 ° s^-1 for the left eye and 5 ° s^-1 for the right eye. (A) The butterflyfish shows no response to the stimulus, apart from a potential small following movement in the left eye (1-3 s). Instead, the eye movements are normal spontaneous ones. (B,C) Both pipefish and sandlances show independent slow and fast phase movements to naso-temporal stimulation. In these animals the response to the slower drum speed (right eye) was not as strong as during temporo-nasal stimulation.