I think we need to read Matthew 5:27-30 instead of just 5:29. The verses cover part of adultery together.
Matthew 5:27-30 (NASB)
“You have heard that it was said, ‘YOU SHALL NOT COMMIT ADULTERY’; 28 but I say to you that everyone who looks at a woman with lust for her has already committed adultery with her in his heart. 29 If your right eye makes you [a]stumble, tear it out and throw it from you; for it is better for you [b]to lose one of the parts of your body, [c]than for your whole body to be thrown into [d]hell. 30 If your right hand makes you [e]stumble, cut it off and throw it from you; for it is better for you [f]to lose one of the parts of your body, [g]than for your whole body to go into [h]hell.
Jesus mentions one eye and hand, and we might value one left or right more than the other, but that’s not the point. Nor is He saying we should mutilate ourselves. We should be ready to sacrifice anything for God vs give into ourselves, using our eyes and hands as we want and commit adultery. That would offend God.