GR translation: zeros happening to coincide with eyes

[Mike Jing]

V583.17-26   After a lot of rigmarole at the door, Bland is finally allowed
in and led through velvet poolrooms, elaborate polished-wood gambling
setups, chrome bars, soft bedrooms, on to a large warehouse section in
back, which is crammed ten high with more pinball machines than Bland’s
ever seen in one place in his life, Oh Boys, Grand Slams, World Serieses,
Lucky Lindies as far as the eye can reach.
       “And every one is fucked up,” sez melancholy Tracy. “Look at this.”
It’s a Folies-Bergeres: four-color lovelies doing the cancan all over it,
zeros happening to coincide with eyes, nipples, and cunts, one of your
racy-type games here, a little hostile toward the ladies but all in fun!

What are the "zeros" here on the pinball machines exactly?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://waste.org/pipermail/pynchon-l/attachments/20150226/5b66df5f/attachment.html>