I was playing ZTris on my TI-84 Plus K-0109N yesterday, I paused the game to do something else and forgot that it is still displaying the pausing screen. When I woke up today, I suddenly recalled that the calculator is still on so I exited the game and returned to homescreen, noticing a darker-than-normal vertical strip on the left side of screen. I tried adjusting the contrast, putting it aside without batteries for hours, but these does not help much. I heard that OLED screen can "easily" get images burned-in, but I never expected such thing to happen on my calculator, which uses a monochrome LCD.
My questions are:

1. Will it disappear over time? Is there anything I can do to make it better?
   
2. Will it have any bad influence on LCD response time/contrast/etc. ?
   

Here is a photo showing the burned-in strip on homescreen:


EDIT: The "burn-in image" have nearly disappeared after days of chilling, it's hardly visible now.

That looks more like lcd ribbon cable failure than burn in to me. Does the dark spot change at all as you navigate the calculator? If so then the ribbon cable is definitely starting to fail. Unfortunately it's a common issue that's impossible to fix without soldering skills. https://www.cemetech.net/forum/viewtopic.php?t=5161

It is unlikely to be ribbon cable failure, I think. The dark spot does become less apparent when characters appear in the leftmost column (when in VARS menu, for example). And scrolling down in CATALOG does not cause abnormal vertical lines to appear, which showed up on my 83+SE with dead ribbon cable.