Six-time MotoGP world champion Marc Marquez has revealed that the double vision he first suffered in 2011 has returned following a violent crash in Indonesia on Sunday, when there were fresh fears for his future after his Repsol Honda flipped 15ft into the air and landed heavily on the track at 125mph.
The Spanish superstar was declared medically unfit with head concussion and hospitalized by his fourth accident of the weekend in Mandalika, which had echoes of a chilling crash that forced him to miss two races last season and caused doctors to urge him to stop racing.
Marquez was also troubled by diplopia following that practice incident in November.
The 29-year-old suffered vision problems on his return journey to Barcelona from Indonesia, making an emergency visit to a hospital after arriving.
Ophthalmologist Dr Bernat Sanchez Dalmau declared Marquez had a "new episode" of diplopia caused by a repeat paralysis of a nerve, although he said there was "less involvement" than the issue he faced four months ago.
"After this examination, it was initially decided to follow a conservative treatment with periodic medical tests," said Dalmau.
"Next week, [he] will undergo a new check-up to evaluate the evolution of the injury and to predict the estimated recovery period to return to competition.”
Marquez told his fans on social media: "It seems that I am experiencing deja vu.
"During the trip back to Spain, I began to have discomfort with my vision and we decided to visit Dr Sanchez Dalmau, who confirmed that I have a new episode of diplopia.
"Fortunately, it is less severe than the injury I had at the end of last year. But now it's time to rest and wait to see how the injury evolves."
Shocked mechanics watched Marquez roll across the track as his bike was destroyed in the crash.
Extreme temperatures at the circuit led to Michelin introducing a stiffer tyre casing for the first time since 2018. The change has been blamed for major rear grip issues for some riders.
"It's been strange because Marc had three big crashes and we have to understand why," Repsol Honda team manager Alberto Puig told Dorna via Crash.
"The crash today was brutal. We need to anaylze. They [Michelin] brought a different tyre here and we need to understand everything. Our rider crashed and we want to understand [why]."
Speaking shortly after the crash, Marquez asked: “What can I say? It has not been our weekend, we have struggled and had problems from the start.
"It was a really big crash in the warm-up this morning – maybe one of the biggest I have had."
He admitted last month: "When I spoke to my doctor, it was my first question: 'If I crash in the Malaysia test, what is the possibility to create the same problem again?'
"And the answer was clear: 'The possibility is the same as you will have in two years. The nerve problem is there. If you crash tomorrow or you crash in two years and you touch that nerve again, it will be damaged.'"