I have phantom images in my imac retina 27 inch

My iMac is showing a phantom images in my 27 inch monitor retina.

My imac shows ghost images that appear on the screen for a while, it's like old monitors that get burned with long use.

Any idea how to solve this, it is not very common and it is resolved with the screen saver but when the windows or images are for a while and then the windows is closed they can be seen slightly like a ghost.

thanks for your help.