Black field test
Backlight Bleed Test
Backlight bleed is easiest to notice on a black field in a dim room. The goal is not to make every screen look perfect, but to see whether bright edges or patches are distracting in realistic dark scenes.
Use the black field
Open Uniformity and choose Black. Lower room light, let your eyes adjust, and look for bright corners, cloudy patches, or light leaking from the edges.
Do not confuse every glow with a defect
IPS glow and viewing-angle changes can shift as you move your head. Backlight bleed usually stays in the same edge or corner even when your viewing position changes.
Compare with real content
If the glow is only visible in a completely dark room on a pure black screen, it may not matter. If it distracts in movies, games, or photo work, document it before a return window closes.