Backlight Bleeding: An LCD Problem
The entire surface of an LCD is backlit from behind by a light source (CCFL light) and the LCD blocks out the light that is not needed. Backlight bleeding occurs when this light is not 100% blocked allowing some light to "bleed" through the LCD causing spots of lighter areas on a dark or black background. Unfortunately, almost all LCDs suffer at least a small amount of backlight bleed because the opacity of LCD panels is not enough to block all light, though it only causes problems if it can be easily detected by the human eye.
Fixing Backlight Bleed
In general, there is no definite fix for backlight bleeding. The best way to fix backlight bleed is to have the product replaced or avoid products's which are known to have bleeding problems all together. Read reviews on the model of product you plan on purchasing, buy from a retailer that will allow you to exchange the display if there are any major problems and if possible try to view a display model or two before you buy. Even this does not guarantee you will receive an LCD completely free from bleeding.
