Hunter eyes are the ideal eyes for men. They are the combination of eyes that are darkly colored, small, "deep set", hooded, have a positive canthal tilt, and have an interpupil distance (IPD) that is within the normal range. The eyes are vertically narrow and horizontally long. The hoodedness comes from a protruding brow ridge and fat tissue above the eyes.
Dark colored eyeballs are also perceived as masculine. A man can have small, dark colored eyeballs but not have developed bones around the eyes and still technically qualify as having hunter eyes. Actor Bruce Campbell has eyes like those.
Conversely A man with deep set, large light eyes, does not have hunter eyes.
Someone with bad eye area is sometimes called an eyecel.
Deep set hunter eyes may be an adaptation for combat, hunting and male dominance competitions, protecting the eyes from fists, claws, sticks etc.