Concern) I suddenly see black fly-like things in my eyes more frequently.

If I keep my eyes open, I suddenly see black flies? Dust? or something similar more frequently.

I think I saw a article saying this is a sign that your eyesight is deteriorating. How should I manage it in such cases?

I hurriedly ordered lutein to try, but I'm not sure if this will work.

I've been worried because my eyesight has been noticeably worsening since my late 30s.ㅠ

Please give me a lot of advice.