My e-ink display has faded. any permeant solution?

My Kindle E-ink display has faded, when I recently checked my Kindle, which I was not using for a long while, I found that the display has been faided really bad. I searched for a solution for this online and found out that keeping it in the freezer will make it dark. And it did work but the solution was temporary. But that gave me the hope that there must be a permeant solution for this. So if anyone knows anything about this, help me to find a solution or if you know the solution please tell me and this will help a lot of people who faces the same problem and I couldn't find a permeant solution for this in the internet so far and there aren't many videos about this so please help.