Just read a paper on LCD mura problems. I now see why it is so difficult to solve this issue.
Mura = Luminence non-uniformity (flashlighting, clouding...etc)
Translation Mura = Blemish
Mura Causes in LCD displays:
1 - non uniform tft thickness
2 - non uniform density of Liquid crystal material
3 - non uniform gap between substrates
4 - non uniform color of color filters
5 - non uniform lamp array
6 - non uniform optical filter
7 - warped light guide/diffuser
Note that OLEDs also suffer from this for different reasons.
Mura = Luminence non-uniformity (flashlighting, clouding...etc)
Translation Mura = Blemish

Mura Causes in LCD displays:
1 - non uniform tft thickness
2 - non uniform density of Liquid crystal material
3 - non uniform gap between substrates
4 - non uniform color of color filters
5 - non uniform lamp array
6 - non uniform optical filter
7 - warped light guide/diffuser
Note that OLEDs also suffer from this for different reasons.