Hello and thank you for your question.
What she is experiencing are called vitreous floaters. These floating spots or "black spots" are tiny pieces of the vitreous jelly that occupies a large amount of the volume of the back of the eye. It sounds as though from her eye doctor saying it is caused by blood vessels behind the eye, that these floaters may also include a hemorrhage into the vitreous jelly. That is a bit more of a complex situation than just plain floaters.
The floaters can take many different shapes which sometimes are as individual as the person having them. They can be screen-like, look like little gnats, in the shape of rings, spider-web like images as you are having or big clumps.
The most important thing to know about these floaters, besides the fact that they usually improve over time, is that uncommonly this process can lead to a break, hole, or tear in the retina, which can then lead to a retinal detachment, which can blind you. For this reason, it is important to see your ophthalmologist as soon as you can for a dilated eye exam to see if there are any problems with the retina. Four signs of a retinal detachment include: sudden increase in floaters, flashing or arcing lights that are persistent and not going away (not a few intermittent ones), a shade/shadow/spot in your vision that you can't see light through, or a large drop in your vision which doesn't improve after a few minutes. For any of these symptoms you must see an ophthalmologist as soon as possible.
With her vision recently worsening, it may be that there could have been interval worsening in the floaters or the hemorrhage and therefore it could signal a problem with the retina. If she hasn't seen her ophthalmologist since this interval worsening I would suggest she see him/her without delay.
Does this help address your concerns?
I am happy to be able to help you today. If you would be so kind, please help me get credit for my efforts in answering your questions and press the ACCEPT button for this encounter. I would also be happy to continue to answer any more questions you have until we have resolved your concern.
Also, any positive feedback and/or bonus you may feel prompted to provide would be welcomed and is appreciated.
My opinion is solely informative and does not constitute a formal medical opinion or recommendation. For a formal medical opinion and/or recommendation you must be examined by your doctor.