Non normal makes a good point.
You may be able to scrape through - the CAA are very positive about getting you through. However you are 15 and the eyes have a few years yet before they stabilise. You could easily deteriorate beyond the renewal limits in the next 4 or 5 years, when they would take it off you.
I think they would be unlikely to grant a dispensation inital until you are a bit older. Which although it's crap now may be in your interests long term.
Good luck
SK