Eye vergence in surface fish while in the dark (A). Higher magnification to emphasize that despite being in the dark and without visual stimuli, the eyes change position (B, D) which, if illuminated, would have largely expanded the binocular proportion of visual space shown in blue (C, E). Notice that eyes converged when prey is detected at a distance (A:0.43 and D), followed by a strike (A:0.86). Soon after, eyes return to normal position (A:1.14). Yellow arrows highlight the prey and red asterisks highlight instances when the eye converged.