From The Verge:

> Its screens offer a respectable 1800 x 1920 pixels per eye with a maximum 90Hz refresh rate, plus new display tech that Meta says offers 75 percent more contrast than the Quest 2’s.

SadlyItsBradley's leak suggests it's a 2160x2160 panel, placed in a diagonal orientation, with a 1800x1920 render resolution.

This was wrong, as he stated in his latest video.

4x comes from higher resolution pass-through cameras

They mentioned that they have higher resolution in the central part of the display, so perhaps this is a variable pixel density display?

VR lenses mean that uniform display pixels result in non-uniform pixels per degree to the eye. Not sure if the effective resolution has changed but almost certain the display panel is uniform pixel density.