With the Bulgarian serving in the early stages of the second set after netting a high quality opener 6-3, the Belgian miscued an attempted backhand volley and the ball flicked up off his racket and caught him in the left eye.
It was quickly apparent that Goffin was struggling with his vision and play was halted immediately. The 27-year-old took a medical timeout away from the court, but he did not return and the umpire announced his retirement to the capacity crowd inside the Ahoy Arena.
Goffin has not enjoyed the best of luck in recent times. He was forced to pull out of Roland Garros last year with an ankle issue after falling over court-covers – and he missed Wimbledon as a result.
He is due to be involved at the Marseille Open next week, but it looks unlikely that he will have recovered in time to fulfil his commitment.
Dimitrov will attempt to win his second ATP 500 title against the soon-to-be world No.1, Roger Federer, on Sunday afternoon.
The Swiss marvel made it through to the championship match after a routine 6-3 7-6(3) win over Andreas Seppi.