Dual programs advice needed

Hi!! I'm applying to JD and MA in international policy programs this cycle. Because I've been so focused on the LSAT, I haven't studied for or taken the GRE. The schools I'm applying to say they're GRE-blind this year (and I know some take the LSAT as a substitute). What does GRE-blind mean exactly? Will not taking the GRE hurt in any way? How is this different than GRE-optional? #help