"If your right eye causes you to sin, tear it out and throw it away" (Matt. 5:29).
These words of Jesus move us to avoid temptations to sexual sin, many of which enter through the eye. Remove and resist visual stimuli that would appeal to a sinful heart.
But the eleventh-century Archbishop of Bulgaria, Theophylact, explained, "When you hear 'eye' and 'hand,' do not imagine that the Lord is speaking of parts of the body, for He would not in that case have specified 'right eye' and 'right hand.' He is speaking instead of those who appear to be friends, but who are in fact harming us. Take, for example, a young man who has friends living in debauchery, and who is harmed by their bad influence. Cut these off from you, the Lord says, and perhaps you will also save them, when they come to their senses. And if you cannot save them, you will at least save yourself. But if you continue in your affection for them, both you and they will be destroyed."
We are reminded in the Small Catechism that God has given us our eyes (First Article). It would not be right or thankful to throw away a divine gift. Far better to see that He has also redeemed our eyes (Second Article) and makes them holy for new use (Third Article).
See your eyes as precious, think of what they are able to do, and resolve not to set before them "anything that is worthless" (Ps. 101:3). Use them to "look at the birds of the air," as He instructs later in the same sermon (Matt. 6:26). Lift up your eyes to the Hill and to the Crucified, from whence come both forgiveness and then help, much help, in the fight against temptation (Ps. 121).
Remember that lust is never satisfied (Prov. 27:20), but that love always finds fulfillment.
If you (or someone you know) seem trapped in sexual sin, seriously consider talking with your pastor. He will hold the matter in strict confidence, offer a listening ear, and share with you God's Word of forgiveness, hope, and help.