Nicotine Stains?

I assume you are cleaning the nicotine off the glasses with something?
I'm sure that if nicotine is on the frames it is or has been on the glass so you want to be sure you do not use anything that is abrasive.

It is easier to clean your glasses if you can clean them over your sink so you can use warm running water (not cold and NOT hot).
Place some mild dish soap (blue Dawn works best - no additives) on your counter along with some clean soft lint-free cloths/rags. You will also need some white vinegar.
First wet your glasses under warm water and add 2-3 drops of Dawn on each glass frame; use your fingers and rub it all over the frames and glasses too; then wet a cloth and rub the glasses and frames under running warm water.
Do this a couple of times and then do the same with white vinegar mixed with water; maybe start with a 50/50solution but go stronger if not removing the stains - keep changing cloths so you are not reapplying the nicotine.
You can use straight vinegar but keep the cloth and glasses wet as you switch between vinegar and running water.
This is usually all you need to do.
Post back if you try everyone's suggestions and your frames are still not clean.
I can say this; there are acrylic frames that stains actually sink into the material and nothing will clean them.
I have found that I can take my glasses back to where I purchased them and they will clean them for free and also readjust them.
Maybe yours will do this for you.