The Bible says:
"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 5:2-30
For an excellent sermon on these two versus, please take the time to listen to Pastor Robert McCurley's sermon:
Dealing With Lust
Recommended reading:
Covenant Eyes: 2014 Porn Stats
Girls Lust Too! - christianitytoday.com
The Entertainment Industry: As Nasty as They Want to Be (my post)
Professor of Pornography Attacks 16 Year Old Pro-Life Activist
Pornography's Link to Sex Trafficking