The splotchy, sometimes sickly, sometimes just bright white, along the edges, aka BLB, is foremost a manufacturing fault, or sometimes caused during shipping. It's just bad design/fitting/knocks that lets the light leak in places, more than others.
Sometimes you get very lucky if you are able to adjust the outer case screws to reduce the leakage.
Can't recall the name of the component that eliminates or reduces BLB that could be added but isn't, because they know it's cheaper to bang out cheap and take some returns... or rather let the seller be stuck with them.
BLB is unacceptable in my book but as we know, it's been part of the PC monitor market for years now. Once we get the FALD tech (upcoming ASUS/ACER), or OLED, hopefully we will see the last of BLB and IPS glow. Although the FALD examples seem to exhibit that halo glow instead....