Jason Smyth quits Florida training base to move to London
Four-time Paralympic gold medallist Jason Smyth has left the training group in Florida which included Tyson Gay.
Former world 100m champion Gay tested positive for a banned steroid in June but Smyth says his decision to relocate to London is unrelated to that issue.
Northern Irishman Smyth is now being coached by 1988 Olympic 4x100m relay silver medallist Clarence Callender at London's Lee Valley Athletics Centre.
"I felt that I needed to be somewhere all year round," Smyth told BBC Sport.
Smyth was diagnosed with Stargardt's condition as an eight-year-old and the disease has left him with approximately 10% of what is regarded as normal vision.
"My needs are slightly more than most athletes because of my visual impairment," added the 26-year-old.
"My summer schedule looked very different to the other athletes (in Florida) with my Paralympic events and the Irish events that I did and crossing paths (with the group) was very difficult.
"This year, I especially felt that living in the States for so long and trying to come back home in the summer didn't work.
"I felt I needed to be somewhere where I can be comfortable where I am and where I know my surroundings."
Smyth added that his departure from the training group coached by Lance Brauman had been "entirely amicable".
"I learned an awful lot while I was there but I just felt that over the last year or so, Florida just didn't quite work for me."
Smyth, 26, opted to link up with Callender after taking advice from Stephen Maguire, who coached the Northern Irishman until the autumn of 2012 before becoming Scottish Athletics's director of coaching.
Smyth had a somewhat disappointing 2013 season, although he did manage to win two gold medals at the World Paralympic Championships in Lyon.
The sprinter's hopes of qualifying for the World Championships in Moscow were dashed as he could only manage a 100m season's best of 10.36 - .14 seconds outside his personal best set in 2011.
"I've got to be confident that I can have a better 2014 and I'm very optimistic," said Smyth.
"I want to make the Commonwealth Games and running the qualifying time for Glasgow of 10.30 is a big target.
"There are also the European Championships in Zurich as well as hopefully going and winning European Paralympic medals.
"It's going to be a busy summer."