The fic that I'm now looking for is a one shot I believe. Or at least a short 3-4 chap fic. 

So this is what I remember. Kryber were dating but Amber broke up with Krystal cause Krystal was just about to debut. I think Amber flies to a european country or something to get over the heartache of letting Krystal goes. Krystal becomes a huge star and all Amber could do was watch the girl from afar. Suddenly Krystal gets into an accident and goes blind. Amber hears the news and gives her eyes to Krystal so that the younger girl may continue to shine brightly on stage. A friend takes, or forcres Amber to Krystal's concert cause the Amber was going to leave again but this time she wasnt planning on coming back. Or something. Krystal receives a bouquet after her concert and knows that it's from Amber thus she rushes out of the concert hall to search for her. That's all I can remember up to. I think I might have mixed up some parts from other fics in here but I can't remember. Oh well. I hope someone or anyone can offer a name to this masterpiece of a fic.