Streaks of light trailing behind a(n apparently) glowing object, body part or entity.

Usually associated with [[glowing eyes|glowing]] [[red eyes|]], especially when a character taps into their super-powered 'evil' side. Sometimes this may also manifest as a trailing light (usually blue or red) behind a weapon with a particularly keen edge.  

In animated 3D media (particularly in video games) this effect is commonly depicted as a trailing particle effect.
glowing streaks