Yes, there are men in existence who are fully committed and devoted to one woman, just as there are women who are fully committed and devoted to one man. The idea of being "only having eyes for one person" is not gender-specific and can apply to individuals of any gender.
Human relationships are diverse and complex, and people have different preferences, values, and experiences when it comes to love and commitment. Some individuals prioritize monogamous relationships and are content and fulfilled by being devoted to one partner for their entire lives.
It's essential to avoid making sweeping generalizations about gender and relationships. While it is true that some individuals may struggle with monogamy or may have different relationship preferences, it is not accurate to say that all men or all people are incapable of being devoted to one person.
Ultimately, the ability to maintain a committed, monogamous relationship depends on individual values, communication, trust, and the mutual understanding and consent of both partners involved. It's important to recognize and respect the diversity of human relationships and refrain from making broad assumptions based on gender stereotypes.