Scientific name for rectangular Pupil?

Solution 1:

The pupil that is considered rectangular has a very unimpressive name: the slit-type pupil. There is a horizontal slit (e.g. goats, octopuses), and a vertical slit.

There is no general correlation between eye size and the presence or absence of multifocal optical systems and slit pupils. Some large-eyed artiodactyls (e.g. Ovis aries domesticus) have multifocal optical systems and horizontal slit pupils (Fig. 7A,B). Horizontal slit pupils are also present in other large artiodactyls such as elk (Alces alces), red deer (Cervus elaphus) and reindeer (Rangifer tarandus) (Fig. 7C; Table 1), as well as in the domestic horse (Equus caballus domesticus) (Kröger et al., 1999). Vertical slit pupils in combination with multifocal optics were found in large and small crocodiles (Crocodylus niloticus and Osteolaemus tetraspis).

They are also referred to as elongated elliptical pupils:

For horizontally elongated pupils, our optical analyses show that the elongation expands field of view horizontally allowing these terrestrial prey animals to see objects near the ground plane both in front of and behind them. Our analyses also show that horizontal elongation allows sharper imaging of horizontal contours on the ground in different directions, particularly directions well off the optic axis. We conclude that elongated pupils evolved to optimize visual information near the ground plane in predators and prey. - Journal of Vision

See Also Investigative Ophthalmology and Visual Sciences