From the Tindie blog:

Breathe New Life into Your Game Boy’s Screen With This Bivert Module

When they first came out, the Game Boy models were the cream of the crop. Even the original DMG model, the screen looked stunning for the time. Despite nostalgia being a powerful thing, the screens haven’t aged well in our post-4K world.

A great way to breathe some life into that screen is to use a bivert module. These modules enhance the contrast of LCD displays by biverting/inverting the pixel orientation on the screen. The difference is pretty noticeable too, with a sharp blue appearance and better grayscale saturation.