Yes - even if your eyesight limitations preclude a Class 1, working at the supermarket would help fund a PPL (which requires a Class 2 medical). In a year or so, try applying for a GAPAN PPL scholarship or an Air League part-NPPL scholarship.
Your approach shows commendable commitment and I wish you lots of luck!
There are RAF Flying Clubs at several stations which offer PPL training at lower cost than civilian flying schools. So, you can still be a pilot in the RAF even if not in a military jet. See
http://www.procommercesolutions.co.uk/raffca/homepage/ for more gen.