  Being fast rotating objects, Isolated Neutron Stars (INSs) are natural
targets for high-time resolution observations across the whole electromagnetic
spectrum. With the number of objects detected at optical (plus ultraviolet and
infrared) wavelengths now increased to 24, high-time resolution observations of
INSs at these wavelengths are becoming more and more important. While classical
rotation-powered radio pulsars, like the Crab and Vela pulsars, have been the
first INSs studied at high-time resolution in the optical domain, observations
performed in the last two decades have unveiled potential targets in other
types of INSs which are not rotation powered, although their periodic
variability is still related to the neutron star rotation. In this paper I
review the current status of high-time resolution observations of INSs in the
optical domain for different classes of objects: rotation-powered pulsars,
magnetars, thermally emitting neutron stars, and rapid radio transients, I
describe their timing properties, and I outline the scientific potentials of
their optical timing studies.
