Grab an object in a video, and a reticle stays on it.
Gaze sees with the fly’s optic lobes
Gaze tracks with the fly’s optic lobes: switch off their 77,530 neurons, and the reticle stays on the object 27% of the time instead of 98%. The columns that run from the medulla to the lobula, among them T2, T3 and the Tm cells, carry a share of it; in the fly, T2 and T3 respond to small moving objects and feed the lobula’s object detector LC11 (Keleş et al., 2020).
Keleş, M. F., Hardcastle, B. J., Städele, C., Xiao, Q. & Frye, M. A. (2020). Inhibitory interactions and columnar inputs to an object motion detector in Drosophila. Cell Reports 30, 2115–2124. doi:10.1016/j.celrep.2020.01.061
In the fly brain
Every video frame reaches the photoreceptors of the fly's compound eyes, and its optic lobes do the seeing.