Hi Jove, thank you for your reply..
My immediate intention is simple +2 (for me, I am just far-sighted), but one of my friends has astigmatism, so the solution to the issue should be inclusive..
I am now trying to determine the optical centre of one of my broken reading glasses lenses (I will try with laser by rolling the holder and lens lightly glued to it so I can adjust the centre as required)..
Then, I will machine it like
this...