Thin blue line on iMac display

[PTplayers]

Hi , I have a 2015 iMac 21inch and for over a year I have a very thin line that is to right of center that comes and goes

has anyone seen this before and if so do you know what it is?



Thank you
Robert
please see attached

 

[TwoH]

It is a fault with the LCD - not repairable sadly, you would have to replace the whole LCD.
It's not a common fault.