a flash or sparkle of light.
Merriam-Webster Online Dictionary
scintillation (noun)1.
an act or instance of - scintillating , especially rapid changes in the brightness of a celestial body
2.
a) a spark or flash emitted in scintillating
b) a flash of light produced in a phosphor by an ionizing event
3.
a brilliant outburst (as of wit)
4.
a flash of the eye