Macbook Air screen flickering

My mid-2012 Macbook Air's has suddenly started displaying random white horizontal bands across the screen. These are not permanent but occur and flicker whenever I scroll in Chrome or perform any other graphically intensive task. This is a system-wide issue and not just application specific, as I can observe choppy animations, laggy transitions and random banding elsewhere too. Because the screen does not show these bands at all times, I don't think it's a fault with the screen - the graphics chipset seems to be the culprit here. Just to be sure, I ran a hardware check and nothing, not even the chipset came out faulty. I'm running 10.10.5. Please suggest how to fix this problem.