Lateral-eyed tree shrews combine panoramic vision with an expanded oculomotor repertoire

Tree shrews (Tupaia) show frequent visually evoked saccades under head fixation, with most saccades occurring without detectable attempted head movement.

• Why it matters: Lateral-eyed mammals are thought to trade away precise, eye-driven gaze control for head-centered gaze, but it is unclear whether lateral eyes or head-centered gaze is the cause.
• What they did: In head-fixed animals, real-time eye tracking quantified saccades and fixation, and widefield calcium imaging assessed visual field representation in visual cortex.
• The result: Visual cortex over-represents the central visual field, and extraocular muscles contain morphologically elaborate palisade endings, implying lateral eyes do not prevent eye-driven gaze control.