You tell him, get the f... away from me and if he persist, go get a track official in-fact tell them he may have a control issue because of his eye and you don't care to race against him,if it's a real issue-maybe the safety of your co-competitors also? They take safety seriously at my track and wouldn't tolerate it especially threats of intentionally or unintentionally taking you out because he can't handle/control his shiz, the place is for enjoyment, not problems, it's not up to you to correct his inabilities, thats what the officials are for.