I had red hot metal flake land on my eye once. Even while wearing safety glasses (the type without the side shields). When I went to the hospital, the nurse was extremely concerned if I could see anything because of how red/puffy my eyes were.

After a 12 hour wait, the doctor had to use metal tweezers and dig it out of my eye. Absolutely terrifying. He said there was rust residue that needs to be removed and would need to go the specialized eye center where they would need to use a specialized drill.

After that, I double up on everything. Not worth it.