The subway surfer who was seriously injured while riding atop a train in Park Slope yesterday has lost an eye as a result of the accident, according to authorities.

The victim has been identified as 17-year-old Isa Islam; he and three other people were spotted riding on top of a Brooklyn-bound F train around 2:20 a.m. on Tuesday morning, and as it pulled into the Fourth Avenue-Ninth Street station in Park Slope, authorities say Islam smacked his head on a metal beam. His co-surfers reportedly fled after Islam was injured, and rescuers identified him using his cell phone; he is now in serious condition at Lutheran Medical Center, where his family has been visiting, and has lost an eye.

Islam's injury comes only a week after a homeless man was killed while subway surfing on a 6 train in Manhattan; the homeless man was allegedly on synthetic marijuana at the time of the incident.