If you have noticed a sudden onset of black threadlike artifacts in your vision in one eye it could be a sign of a serious eye condition especially if it comes with flashes of light in your vision – you should see you Optometrist however if you have gradually seen more floaters in your vision, it is usually a normal thing. The floaters are created from cells at the retina coming away and floating into the gel of the eye (known as the vitreous) you are not actually seeing the floater but a shadow of them. Therefore, they are rarely seen in very low light