Has anyone else noticed a digital burn of the keyboard on their iPhone 6 screen?

My iPhone 6, which ive used since last September has developed a digital burn of its keyboard onto it's screen, much like an old TV or computer would get a news station logo or icon imprinted/ burned into its screen. I was wondering if anyone else has had this problem, and if no one has noticed it yet, it is cerysinly something that Apple should dl fix for future iPhones. I do not use my phones keyboard as oftem as some people do, so it surprises me that this happened to my phone.