I like Ole's ancient hand drill method.
It has TWO levels of safety factor...the slow speed and the requirement to mount it because the drill requires two hands, thus you don't have it turn into your flesh if the bit grabs.
Now I am assuming one safely mounts the board to a safe work surface and doesn't hold it between ones knees!
If I didn't mention it previously, I measure the desired diameter with a digital caliper, visually set the flycutter bit to the caliper spacing, make a test drill partway thru a scrap piece of target lensboard material and recheck the measurement/adjust as desired.
This also gives me a preview of any blade cutting clearance (is that called kerf like wit a table saw blade?)...in other words, it reduces the number of surprises and vocal outbursts.