Hyuuga history

The hyuugas (angelic) has the Byakugan (白眼, Byakugan? literally "White Eye," Viz "Evil Eye") which is a special pupil condition (瞳術, Dōjutsu?, literally "eye technique") that naturally occurs in members of the Hyuga clan (and thus only characters from the Hyuga clan possess it). Byakugan users are characterized by their lavender, pupil-less eyes. When the Byakugan is activated, their pupils somewhat appear and the veins near their temples bulge.

A person with the Byakugan has a nearly 360 degree field of vision, except for a small blind spot behind the first thoracic vertebra (near the back of the neck), which is its only known weakness. Byakugan users can detect anything around them within a 50-meter radius (able to increase radius), making them close-range combat experts. The Byakugan also gives the user the ability to see through basically any matter over extremely long distances. This seems to be a combination of x-ray and thermographic vision. A small degree of telescopic vision is also present, as a Byakugan user can focus on a single object at any point within their range of vision. The degree of focus seems to be dependent on the skill of the user. The Byakugan's sight cannot be blocked, except in the case of something like Ranmaru's kekkei genkai ability, unlike the Sharingan, which can be blocked by any sufficiently opaque substance. It is however, possible to impede it slightly through the use of certain powerful seals. The Byakugan's insight capacity makes it useful for searching, tracking, and identifying targets.

One of the most powerful aspects of the Byakugan is the ability to see the inner chakra coil system, which is the key aspect of using the Gentle Fist style to attack said system. If sufficiently developed, the Byakugan is able to see individual chakra points, potentially allowing the user to shut off the opponent's chakra flow completely, such that the opponent cannot perform techniques that require chakra. However, the user can increase chakra flow as well. Seasoned Byakugan users are even capable of killing with a single blow.