I’m Ryan Ressmeyer, a PhD student in Bioengineering at the University of Washington, working with Greg Horwitz and Jacob Yates. My research sits at the intersection of eye movements and early visual processing: I build high-precision instruments to measure how primates look at the world, and I use them to study how the thalamus transforms retinal input during natural, active vision.

Two threads run through my work. The first is methodological — most of what we know about visual cortex assumes a still eye, but the eye is never still. I developed OpenIrisDPI, an open-source digital dual-Purkinje eye tracker, to make sub-arcminute eye tracking accessible to other labs. The second is scientific — using Neuropixels recordings in awake macaques, I’m asking how the lateral geniculate nucleus gates and reformats visual signals around saccades.

Before Seattle I studied electrical engineering at Stanford, where I worked on wearable eye-tracking hardware in the Otoinnovation Lab. I’m supported by an NSF Graduate Research Fellowship.

This site collects selected publications, my CV, and a blog where I write about research, tooling, and things I’m thinking through.