Error in screen Macbook

Since a few weeks there’s a lighter area on my screen, in the middle. I have no idea where it comes from and certainly no idea what to do about is. Does anyone has an idea what it can be?

I have had this issue before with an LCD screen where pressure had been applied on the screen during transport, i.e. screen leaning against a seat arm rest.

Would there have been anything pushing in front or behind the screen at any stage?

A few examples to give an idea:

[li]A child or someone else accidentally poked the screen while pointing something out.
[/li][li]A heavy object was placed on the screen lid while down.
[/li][li]An attempt to close the screen while something was on the keyboard.
[/li][li]A solid item placed above the screen in the laptop bag. E.g. power plug, mouse, etc.

I think there must have been something heavy on top, or a solid item above the screen in the bag. Probably nothing I can do about it now accept have it fixed? Don’t think I will, must be very expensive…