I don't think it's the amount of TV or screen time that affects your vision, but the way you're doing it. Like if you are in a dark room that brightens up and you're up close, that's definitely going to affect your vision. It's putting strain on the cones and retina within your eyes. But if you're like in a normal lit room, just chilling back on the sofa, the TV's on the other side of the room, I don't see that having any difference whatsoever.