Fix uniformity-issues with 'Own' lightning?

[Oled]

I have problem with one of my monitors. I really like the picture but one thing that bothers me is that the lightning increase the lower you go on the monitor. (Note this is not caused by bad viewingangle or backlight bleed.)

I wonder if there is any way to fix this?

Can I include own lights i the monitor chassi to make the lightning more even?

Is there any other good way?

Apart from the lightning I really like the monitor so it would be a shame to throw it away.