A laser is not a very productive way to etch glasses, especially if you do them all the way around. You have to have a rotary attachment and it's a fairly slow process. Some people do it. Some people say it works great. However, you cannot begin to compare the quality between lasering glass and sandblasting it. The laser is actually creating tiny fractures in the glass to make the image. It basically heats and explodes the glass pulse by pulse.
You end up with a finished product that is shards of glass, tiny shards. They like to end up embedded in your skin.
For the sandblasting, there is a process that creates the template using UV light. You wash it out with water and you can have all the detail you want. Same pattern can be produced over and over and over. You apply the resist film, then blast it and remove the film. You'll never make money cutting them on the plotter for a quantity of glasses. It's just not the most economical way to do it.
Check out Rayzist's website. They have demos online and all the methods and products.
Just my opinion.
