Black pixels appearing on screen

Hello,

The past few days when I open my macbook after its been asleep and I log in, a line of black pixels are appearing the length of the screen lasting 4/5 seconds. Ive also noticed if I hit the power button to put it to sleep this bar has been appearing before all the colour fades to black.

Anyone else had this? should I make an appointment at the genius bar and get it checked?

Hope this makes sense! Thanks 🙂