[kanetw]

The above formula only holds for diagonal FOV, which is higher than hFOV/vFOV.

The formula for e.g. PPD in the h-direction, assuming uniform pixel distribution, would be hPPD = hRes / hFOV. With a uniform distribution, 2448px at 100deg FOV would be 24.5.

We don't have uniform pixel distribution, as the human eye cannot resolve well where it can't gaze. So we magnify more wherever you can actually point your pupil at, and less towards the periphery. That way we retain eye-acuity while allowing us to "waste' less pixels where they aren't required.

We maintain >32 PPD within +- 15 degrees of eye rotation, which accounts for 86% of eye rotations.