Macbook Air Screen with dark vertical line on side

My mac's screen has this dark area on the right side of the screen. It appeared one day and has happened two other times now. It begins flickering a bit and randomly appears and disappears. If I stay on a screen too long, whatever was on the screen gets 'burned' into the affected area (look at the image attached, you can see the dropdown button burned into it). Does anyone know what the cause of it is and how to get it fixed?

Edit: Restarting the laptop does not make it go away.