A:
You probably have benign vitreous floaters. These are very common and often occur as we age. Vitreous is the jelly-like substance in the center of the eye, in front of the retina. As we get older, the vitreous tends to collapse and pull away from where it is attached to the back of the eye. If the vitreous does detach, a person may notice black spots, squiggly lines and sometimes flashing lights.
Usually the spots and lines quickly go away. But for some people the symptoms stay longer. It always a concern when this happens. Black spots could also appear if there was some bleeding into the eye. Although uncommon, when the vitreous detaches it can cause a retinal tear. In rare circumstances, this can lead to a retinal detachment.
If you still see the spots and lines, contact an eye specialist (ophthalmologist) to be certain your floaters are just the benign type.