Disappointing that more analysis isn't put into the lense effect on PPD. SimulaVR (a competitor) has an extremely good blogpost about this [1] where they argue

Disappointing that more analysis isn't put into the lense effect on PPD. SimulaVR (a competitor) has an extremely good blogpost about this [1] where they argue that the PPD in the central 30 degrees is far more important than the average PPD over the whole headset (because you very rarely turn your eyes more than 15 degrees off center, and your eyes have the highest resolution right in front of them), justifying the same sort of lenses that Apple appears to be using. They claim that this allows them to reallocate pixels for ~45% higher "foveal PPD" than would otherwise be expected. [1] https://simulavr.com/blog/ppd-optics/ https://simulavr.com/blog/ppd-optics/