what eye powers? Granted I never even got halfway through any of the games, but I'd never heard anything about eye powers.
Do you know those abilities in Naruto like Haku's ice powers, Gaara's sand powers and the Sharingan?
It's the same deal.
Hibari's family is a famous clan of Good Shinobi whose blood carries these eyes inherited by birth.
It's not very well explained in the serious, less light hearted games but I have a theory that it probably lets the user control the mind of the victim, and I think Hibari can't use it properly or does not know its full potential.
Hibari used it on Haruka once and Haruka became much less intelligent and talked like a robot, but still fought back.
I could be wrong but Kagura seems to have the same eyes.