Weird Screen Problem

[costeta]

There's a weird, slightly grey-out splatter inside the screen of my 2010 mbp. It is not visible when the computer is off. I've inspected the screen when it is off and it is squeeky clean--no scratches or stains. I've even inspected it using a flash light in a dark room and it is squeeky clean. However, when the screen is on, it shows this whitish greyed-out splatter when the screen is showing black or dark images. I played a black screen video on youtube and it shows the splatter. It doesn't show on white, pink or blue backgrounds, just black or dark backgrounds (attached pictures). Could this dead pixels developing in the screen? There is no surface damage on the screen

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