When Open Firmware Meets Open Vision: A Builder's Note on Polyend and Amblyotube Polyend open-sourcing the Tracker firmware hit Hacker News at 93 points this week. The thread is exactly what you'd expect — developers dissecting MIDI implementations, dreaming up custom sequencers, calculating latency budgets for community forks. I read it on a Thursday evening, Quest 3 on my desk, Amblyotube sideloaded and running a dichoptic session against a YouTube playlist of 80s synth demos. The parallel struck me: both projects bet on the same premise — that the community will build things the original team never imagined. Polyend gave away the Tracker's C++ firmware, HAL drivers, and USB descriptors. We gave away the platform choice — building on Meta Quest's open SDK instead of locking into a $2,000 proprietary goggle ecosystem. Technically, Amblyotube exploits Quest's dual-display pipeline: two independent render passes, one per eye, composited at 72–90 Hz. The dominant-eye shader (configurable blur/contrast/gamma/opacity) runs as a fragment pass; the lazy-eye sharpener uses an on-device MediaPipe pose model to detect human silhouettes and apply selective unsharp masking only to that eye's texture. Wedge occlusion is a simple stencil mask. The magenta fusion cue — a moving circle at #FF00FF in the weak eye, #888888 in the strong — exploits opponent-process theory to drive binocular rivalry resolution. All tunable at runtime via a hand-tracked control panel. No recompile needed. The LogMAR vision check uses a staircase algorithm across 30 Landolt C trials at virtual 3m — clinically grounded, not marketing fluff. Presets (Mild/Moderate/Severe) map to shader defaults automatically. 30–40 min/day. Ages 13+. Supplementary tool, not a cure. Open platforms let niche use cases survive without vendor permission. That's the whole thesis. https://www.meta.com/en-gb/experiences/amblyotube/25906906972338493/