Second anons saying Holy Spirit, self control, etc.etc. if i can while probably still having a log in my eye most of the time although not that I've used it, but this extension could be useful http://www.pluckeye.net/
Not a porn blocker as such, although it is, but only a temporary one: I believe you turn on a filter but it's only time limited so you'll try to go on something but it will block it for, say, the next few hours until (you set the time limit) until you've cooled off.
>Pluckeye, the way of life
> Ye have heard that it was said by them of old time, thou shalt not commit adultery: but I say unto you, that whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart. And if thy right eye offend thee, pluck it out, and cast it from thee: for it is profitable for thee that one of thy members should perish, and not that thy whole body should be cast into hell. And if thy right hand offend thee, cut it off, and cast it from thee: for it is profitable for thee that one of thy members should perish, and not that thy whole body should be cast into hell.
>– Matthew 5:27-30, KJV
http://www.pluckeye.net/what-is-pluckeye.html