Get done an eye examination with retina specialist. Doesn't seem urgent. But yearly one comprehensive eye examination is must I would say.

The black things in your vision which you are describing are called "floaters" in medical terms. Usually they are harmless but annoying as they obstruct the vision. However if you have a shower of black dots, flashes of light or you are unable to see clearly in any portion of your vision then you need to consult a doctor. If you have high minus power then there are chances that there are weak areas in the retina.

It may be floaters .if you are continuously experience of these symptoms with flashes of light. It's better to consult a retina specialist

These might be floaters, they are small opacities in the vitreous ( jelly in front of your retina ). These are absolutely normal.