\tangent I've always loved the idea of eye-tracking. It helps the whole graphics stack, because don't need to render the whole "screen", just the exact part you

\tangent I've always loved the idea of eye-tracking. It helps the whole graphics stack, because don't need to render the whole "screen", just the exact part you're looking at. And you only need render the center of it in sharp detail (what impinges on your hi-res fovea); the surroundings can be blurry and even monochrome (no cones outside the fovea, only rods!). Unfortunately, because eyes saccade (twitch) extremely fast, latency must be ridiculously low or it would send you insane (figuratively).