While playing soccer on artificial turf (crumb...

While playing soccer on artificial turf (crumb rubber will be used and scattered on the grass) I felt a tiny piece of rubber get inside my eye. Now I didn't feel that it went out, but there was no pain whatsoever so I continued to play normally and forgot about the whole thing. Next day I tried to rinse my eyes in various ways but still nothing came out. I used my finger and examined the outer side of my eye lids in both eyes to see if I can feel anything hiding there. I felt a tiny little thing move fast (https://imgur.com/a/gU2FQHD) and then nothing. I scheduled an appointment with an eye doctor and he suspected that a little piece of rubber scratched my eye, however after several tests, he didn't find any scratch. He even flipped my eye lid and examined my eye and didn't find anything and he just gave me some drops to moisturize my eyes but I can swear I can feel something is there. Specially when I put my finger in the described area No pain in anyway, but sometimes when i wake up in the morning (around 5/10 times) i can feel discomfort as if there is indeed something in my eye. the feeling goes away within 15 minutes or so. What can i do to make sure there isnt something in my eye ? is that piece of rubber will be harmful for me in the future if nothing was done ?