Magnifier lamps can be useful.  I have one on my Delta 17" drillpress that
mounts with a 5/16" arm and has an adjustable swivel.  Its really useful for
centering small drill bits.  However, for any really finicky small projects,
I had my optometrist order a pair of bifocals which focus at 6" on the
bottom and 18" on top.  The bottom bifocals have a 6 power magnification.
They were no more expensive to make than my reading glasses, and work great.
With the 6x magnification, I have no problems seeing the numbers on the
shanks of small number drills.  I had the lenses made to order for a pair of
antique eyeglass frames with wire temples.