  A general asymptotically-flat, static, and spherical symmetrical wormhole
without a thin shell has at least one unstable circular light orbit at a
radius. If the wormhole has $Z_2$ symmetry against the throat, the stable or
unstable circular light orbit must be on the throat but this fact is often
overlooked. In this study, we categorize the numbers of the circular light
orbits of the $Z_2$-symmetrical wormhole and their stability from the
derivatives of an effective potential at the throat and we investigate the
circular light orbits around a Simpson-Visser black-bounce spacetime, a
DamourSolodukhin wormhole spacetime, a Reissner-Nordstr\"{o}m black-hole-like
wormhole spacetime or a charged Damour-Solodukhin wormhole spacetime as
examples. We give complete treaments including degenerated circular light
orbits made from more than one stable and unstable circular light orbits on and
off the throat.
