Screen problems on original GameBoy

[PanMan]

Hey guys, since you are all pretty knowledgable about games and systems, I was hoping you could help me out with a little problem I have with my classic GameBoy. Essentially the screen is getting ruined. I cannot see what is happening on the left side and the right side. I have some pics below to help illustrate my point.


Before:


After:



It seems like it is getting worse over time, but I don't know what is causing it or what to do to slow it down or stop it completely. I assume there is no way to fix it without replacing it, but was wondering if anybody here had any insight. I keep a game in the slot all the time and the GameBoy is stored away from dust and at room temperature if that helps. There are also no batteries in it and there is no physical pressure on the screen or anywhere else on the GameBoy.

Thanks in advance for any help.