word verification

I don`t believe I`ll spend much time visiting blogs with this word verification.After one or two attempts to leave comments,I give up.This morning I spent 4 times writing exactly what the words said,& still couldn`t leave one.I feel I`m going blind trying to read them,then they sometimes have numbers too?are you to copy them when that`s not a word,or is it a trick to prove you ARE a robot?