Banks Martin S, Sprague William W, Schmoll Jürgen, Parnell Jared A Q, Love Gordon D
Vision Science Graduate Program, University of California, Berkeley, Berkeley, CA 94720, USA. ; School of Optometry, University of California, Berkeley, Berkeley, CA 94720, USA.
Vision Science Graduate Program, University of California, Berkeley, Berkeley, CA 94720, USA.
Sci Adv. 2015 Aug 7;1(7):e1500391. doi: 10.1126/sciadv.1500391. eCollection 2015 Aug.
There is a striking correlation between terrestrial species' pupil shape and ecological niche (that is, foraging mode and time of day they are active). Species with vertically elongated pupils are very likely to be ambush predators and active day and night. Species with horizontally elongated pupils are very likely to be prey and to have laterally placed eyes. Vertically elongated pupils create astigmatic depth of field such that images of vertical contours nearer or farther than the distance to which the eye is focused are sharp, whereas images of horizontal contours at different distances are blurred. This is advantageous for ambush predators to use stereopsis to estimate distances of vertical contours and defocus blur to estimate distances of horizontal contours. Horizontally elongated pupils create sharp images of horizontal contours ahead and behind, creating a horizontally panoramic view that facilitates detection of predators from various directions and forward locomotion across uneven terrain.
陆生物种的瞳孔形状与生态位（即觅食方式和活跃的昼夜时间）之间存在显著的相关性。瞳孔垂直拉长的物种很可能是伏击性捕食者，且昼夜活动。瞳孔水平拉长的物种很可能是猎物，眼睛位于两侧。垂直拉长的瞳孔会产生像散景深，使得比眼睛聚焦距离更近或更远的垂直轮廓的图像清晰，而不同距离的水平轮廓的图像则模糊。这有利于伏击性捕食者利用立体视觉来估计垂直轮廓的距离，并利用散焦模糊来估计水平轮廓的距离。水平拉长的瞳孔会使前后的水平轮廓产生清晰的图像，形成水平全景视图，便于从各个方向检测捕食者以及在不平坦地形上向前移动。
