Paul Scholes has admitted he may never totally be free of the blurred vision which brought a premature end to his season.
The Manchester United midfielder has not played since being sent for a scan by Sir Alex Ferguson following the Red Devils' Premiership draw with Birmingham in December.
At the time, Ferguson admitted specialists had been unable to diagnose the precise nature of the problem, other than it was unrelated to football, and ordered Scholes to take a complete rest.
The former England star has now resumed light training, although he has not yet started contact work and will not play again this season.
However, the 31-year-old is determined to be ready for the start of the next campaign even though the problem may not have totally gone away.
'It has not completely gone yet,' Scholes told Century FM.
'It has been four months now, so I am not sure it will be completely normal but I should be okay to start playing again.
'I don't really know why it happened. Apparently, it is something quite rare in people my age.
'Unfortunately, it has happened to me and I just have to get on with it.'
Apart from providing United's goalkeeping contingent with shooting practice, Scholes has also been given a series of exercises for his eyes which have eased the blurred vision.
And Scholes sees no reason why he should not be back in action in time for United's pre-season tour to South Africa.
'My aim now is for next season,' he said.
'As long as I am ready for then I will be happy.
'I was a bit worried but it has been more frustrating than anything else because, while, as a footballer, you expect to pull muscles, this was something completely different.
'I never really thought I had played my last game or anything like that. I was just focused on getting it right and the sooner I could get back the better.'