Irish Paralympic sprinter Jason Smyth has been reclassified from the T12 to T13 category, just ahead of the Paralympic Athletics World Championships in Doha, Qatar.

Smyth is the reigning world and Paralympic champion in both the T13 100m and T13 200m, as well as the world record holder in both events, but was reclassified to T12 in 2014 ahead of the European Championships, where he won gold in both events.

T12 classification would indicate that the athlete in question can recognize the shape of a hand and perceive clearly up to 2/60. The visual field of the athlete is less than 5 degrees, while T13 classifies the athlete as being able to recognize the shape of a hand and can perceive clearly above 2/60 and up to 6/60. The visual field of the athletes varies between more than 5 degrees and less than 20 degrees.

A spokesperson from the International Paralympic Committee said: “When Jason Smyth was classified ahead of the European Championships in 2014 he was found to be on the borderline of the T12 and T13 classes.

“All of the results of the assessment placed him in the T12 class. He was however placed under review status. The review was conducted this week and his results were again borderline, but all were in the T13 class so he was moved back.

“Vision impairment tests can be influenced by a number of environmental characteristics. As last year’s result came as a surprise to all concerned, the IPC acknowledges that in retrospect it should have asked Smyth to undergo a second classification at that time.”

Smyth will now be able to defend his T13 100m title at Rio 2016. However, the T13 200m has been removed from the list of events at the Games by the IPC.

Smyth said of the decision: “It was a surprise to me last year that I had been moved to a T12 and was difficult to deal with, so I’m pleased that my status as a T13 has been clarified and I won’t need another review until 2019.

“However it is disappointing that I definitely won’t have the chance to defend two of my Paralympic titles in Rio as the T13 200m has been removed from the list of Rio medal events by the IPC.

“That said at least I can put all my energies in the 100m and continue to try and run faster and bridge the gap between Paralympic and able-bodied sport.”

Smyth will compete in the T13 100m heats this Friday at the worlds in Doha, with the final scheduled for the following day.

The T13 200m heats in Doha will take place on Sunday, with the event's final taking place next Monday.