The FAA doc and Whirls are both correct. At your somewhat advanced age, it is silly to shell out a cent for training until you figure out if you're physically qualified since you say you have vision issues.
Don't know what a Class 1 Medical runs in the UK, but in the U.S. I get my FAA Class 1s with ECG for about US$130. A small price to pay to prevent shelling out thousands for training you may never be able to use. And, until you hit 40, the Class 1 turns into a Class 2, as Whirls points out.