Any optician dispensers here? What do these numbers on my frame mean?

[Miljea]

Can you interpret the numbers, please?

The 52 is the lens size the 20 is the bridge and the 140 is the length of the sides. The other numbers are probably just the frame code.

To explain it better: What those three numbers mean: the first is the width of each lens at its widest point; the second, the distance between the lenses (the nose bridge). The third is the length of the temple, the piece that fits over your ear. All these measurements are in millimeters.
This is exact, but does not mean an exact fit! There are other parts of the frame that will change how it fits on each person, including how it sits on your nose (high or low), extra frame material to connect the temples, curvature of the frame, style of frame (rounds have more narrow lenses), and so on. You could easily find two different frames with the exact same measurements, but one might fit you and the other might not, while two different sizes in different models could easily both fit well.
It does give a starting point, however; if a 52 eye size fits you well, it’s unlikely that a 58 will (though you might still try 51, 53, 54 and maybe even 55).

Thanks very much!

Found this arm of old specs lodged in a bin; specs that fitted well but where the frame broke in early April 🙄 Optician managed to find another frame to fit my lenses in, which I've been wearing ever since, but I call them my Covid Glasses as they don't fit that well.

Wanted to have a new 'base' from which to choose new frames after a new eye test next week.