Magnifying the eye

Came across something which told me that adding a plain magnifying glass tot he front of your standard zoom would give the option of focussing really close - almost turning it into a macro lens.

Trials determined that either:
a: I was doing it all wrong,
or
b: It was a load of rubbish and only worked on the one particular lens that the articles author happened to be using.

Most likely the answer is "a" and I need to play a little more to work it out.

I was playing with the magnifying glass and wanted to get something for my blip today, so I grabbed eldest offspring. He was on the trampoline and tried to get jumping pics. It's a fair bit of fun, but trying the jumping with a camera in front of your face isn't the wisest thing to do. Eventually, I got him to stop and hold the glass steady(ish) in front of his face to capture this.