Where is the Brightness (Black Level) setting? Reduce that. And then start again.
Please be advised that some manufactuerer's Advanced Settings stuff takes control of the Backlight Level, disregarding where you set it. Like Dynamic Contrast Ratio as one example.
Brightness Level (Black Level)
Contrast Level (White Level)
The Brightness Level and Contrast Level has no effect on longevity and does not hurt the set. The Backlight Level, generally you hope that you dont have that full blast, so as to save life on the lamps. Over the life of the unit, (were talking decades) you will have to keep turning up the Backlight Level to keep a constant lumen output as the bulb wears itself out.
Epson 8350 / Panasonic AX-200u / Optoma Graywolf 92" / Draper Luma 92"
Samsung 51F8500 / Panasonic P50ST60 / Vizio P502ui-B1 / Sony 50W700B LCD
Sony S790 / Panasonic BDT-220 / Roku 2 XS & Roku 2
Samsung F550 / Speakercraft CS3 / Yamaha YAS-105