I'm not really sure if they are growing but sometimes the larger ones seem darker and other times they don't bother me as much but they don't go anywhere they are still noticed on most backgrounds. Outdoors or in brightly light areas, the floater is impossible to see through but sometimes I can see through it a tiny bit and it seems more a shade of dark grey than black. The only thing I notice about my oldest and darkest of my floaters is that it has 3 strands attached to it and there are little transparent dots that are near that particular floater.