A more substantial problem is that diffraction limits the effective resolution of an optical system to well above the size of each of these pixels. This is a problem with current sensors at narrow apertures; lenses exhibit a measurable loss of sharpness, typically f/11 and up, because the airy disks expand as the aperture contracts. With hugely dense sensors like this, though... plugging some numbers into a website that explains the whole situation suggests that you'd need to shoot with apertures than f/1.8 to get circles of confusion smaller than the size of a single pixel.

That's right--even "fast" f/2.8 lenses are limited by physics to never being able to project detail onto individual pixels. You could potentially add a deconvolution stage in software to recover additional sharpness, but not in hardware.

Another thing. Do the math: the pixels are 2.1 micrometers square. Compare to trichromatic human vision, which detects red light peaking at 564 nanometers, 0.564 micrometers. The size of a pixel is within a factor of four of the wavelengths they measure. Staggering.

Glass isn't the problem. We need new laws of nature, since we're near the edges of the ones we have now.