Lump on the side of goldfish...

I have been away for three days and have just discovered that one of the
three goldfish that live in a BiOrb (Yes, I know!), has a lump about the
size of half a pea protruding from the middle of its length on one side.
There is also a slight bump on the other side too. I can't see any outer
breaks in the skin. Might be worth adding that over six months or so his
left eye has gone blind as it has shrunk to a small dot; hasn't appeared to
cause it any distress.
I don't feel too hopeful for him really as this is so sudden. Any
thoughts/advice please?

Thank you in advance,

Nick