I think mine were. I strained my eyes really bad over days of work, and then one day before going to sleep rubbed them. When I opened the eyes, I seen a brown clot in the middle of vision which after a month of treatment with eyedrops fell apart into lots of floaters / worms. 2 years later most of them dissolved, but some remain and vision is blurred a bit. It also turned out that most people I asked have floaters too, but if there aren't many, they're filtered out by brain. If you aren't looking for them specifically, they aren't visible. They are hard to unsee though once you seen them, so better not to try. )
Eyedrops name of which I don't remember, but I can try find if needed as they're commonly prescribed in Russia for this condition. I wouldn't recommend them though as turning a single clot into long wormy things was scary and annoying. I seen similar complaints from others who were prescribed these eyedrops. I'm not sure if they helped with dissolving the floaters, as I had smaller recurrence recently and not used any eyedrops and it's still slowly going away. Btw, if floaters are in the center, try moving the eyes up and down 10 times in succession - most of them should stick outside of vision.
The eye doc said it was just some pieces of the inner eye drying with age, and normal.
I don't believe they were screen related, I just hated seeing them. I either got used to them after a couple years, or maybe the pieces have settled out of sight, as they don't bother me much anymore.