  I review the effects of dust obscuration in galaxies at both low and high
redshifts, and briefly discuss a method to remove dust reddening from the
emerging light of star-forming galaxies. I also analyze the evolution of the
dust opacity in galaxies as a function of redshift, and discuss its effect on
the observed UV-optical light. The quantitative corrections for dust
obscuration given here allow one to recover the intrinsic value of the global
star formation at different cosmological times.
