Loctite, who makes Cyanoacrylate (crazy glue), says that it can be removed with acetone. However they also make a solvent for Cyanoacrylate, it’s basically nitromethane with a little toluene thrown in. I don’t know if you can find it but their web page shows the product number as 76820 - X-NMS Clean Up Solvent for Instant Adhesives (Nitromethane), 2 Fl. Oz. Bottle
Or look for “Duro Super Glue Remover” w/ product nos:
01-32249 - 5ml tube (Canada)
01-80844 - .34 oz. Tube (10 ml)
01-81754 - .34 oz. Tube (10 ml)
Might be easier to find…
If you can’t find those, and the acetone didn’t work, better hobby shops sell nitromethane as fuel for model airplanes. Find a bottle of 100% nitro, see if they’ll let you dip a q-tip in it, and try it!
This may of course damage your sunglass lenses if they are plastic!! Glass lenses should be safe, though.
Apply acetone with a q-tip and keep dobbing it on to keep it wet / pooled with acetone for a minute or two. Then take a popcicle stick or something stiff (wood or plastic like a small wax comb - not metal cuz it scratches) and “scoop” at it. It should work off if you let the acetone pool on the spot you’re trying to rid to let it dissolve.