Hi Luis, The word "Intense", in this context is meaning captivating, engaging eyes that the person is drawn to noticing. Very noticeable eyes that appear to show the man may be an intense character. I hope this is helpful. Best regards, Maria.

The closest synonym is "serious." If I were going to draw a picture, I would draw someone with their eyebrows drawn low and close together.

It can also mean having a strong look or stare as opposed to soft relaxed gaze

Probing. Showing that he is analyzing everything he sees.

Intense means having or showing very strong feelings.