Try using the powder coat you can buy at Bass Pro and the like for lead jigs. It is a powder paint. I use an alcohol lamp and an old pair of tweezers then holding the eyes with the tweezers, hold them in the flame for about 5 seconds then push them into the powder (red) pull them out ASAP and their done. If you want a black dot in the center use the head of a nail dipped in testers model paint to put a dot in the center. Different size nails different size pupils.

I use this for lead, brass, and bead chain eyes for closers. I'll sit down and do several dozen then go tie.

Dan