Blurry Horizontal Lines

Hello, when I am using lights to light up my animation I get blurry grey horizontal lines on the screen in istopmotion. When I turn the lights off the lines disappear? But of course that’s not ideal because I need the light to get rid of shadows etc. I’m not sure if it;s because the lights are halogen work lights or if there its something to do with frame rate or interlacing? Anyone have this problem? The camera I use is an iPevo web cam which has always worked fine.

can you please attach a screenshot of this so we can try to understand whats happening?

Thanks for coming back to me…here is a screen shot - can you see those blurry grey horizontal lines?