Fig. 5
From: Crown-of-thorns starfish have true image forming vision
Crown-of-thorns starfish perception of the black-and-white circles at varying distances. a Visual representation of the stimulus and the field of view of a single eye at varying distance between the starfish and the stimulus. The numbers indicate the distance of the eye to the stimulus in centimetres and the red lines mark the outline of the visual field. The stimulus circle shown here has an angular height of 37° seen from the centre of the arena. b Relation between the proportion of white in the field of view and the distance to the stimulus. Note that at close distance to the stimulus, the white area sampled by the eye was twice the size of the sampled black area