Naisho Byakugan

The Naisho Byakugan (内緒白眼 Hidden White Eye) is a rare form of Byakugan that appears in half hyuga members. It has all the same facets as the Byakugan except that when it is inactive the user will have normal eyes. Because of its hidden nature many have sought after it for themselves.

Background
This oddity occurs only under unique circumstances. Firstly a man from the Hyuga clan must have two dominant alleles toward his Byakugan. And secondly he must copulate with a woman who also has two dominant alleles for her eyes. The resulting child will be imbued with the Naisho Byakugan. The Hyugan clan looks upon the children with disgust and usually has them aborted or there eyes destroyed. As a result these incidents are usually kept a secret from the main family.

Abilities
The primary ability of the Byakugan gives the user a near 360º field of vision, except for one blind spot at the back of the neck above the first thoracic vertebra.Upon activation of the dōjutsu, the wielder is granted an automatic 50 metre field of vision around themselves which can be extended through training as Hinata Hyūga's range in Part II stretches to at least as far as 10 kilometers.

The Byakugan is also able to see through solid objects and smokescreens, even through most barriers as only a particularly strong barrier such as the Four Black Fogs Formation is able to somewhat distort the Byakugan's perception. It can also differentiate between non-corporeal clones and see through techniques that would otherwise hide an opponent from normal sight. The dōjutsu also has the ability to follow high-speed movement. In the anime, the Byakugan was also shown able to magnify objects to see the smallest of targets in the area and see in infrared to detect a target's body heat.

Arguably its greatest ability is to see chakra in all its nature, including its flow and the circulation system inside the body with great detail as well as the colour of chakra. Like the Sharingan and Rinnegan, the Byakugan can detect chakra sealed barriers as well as determine when genjutsu is being used. In the anime, the Byakugan can also discern a transformation from the real person through their chakra. Constantly using the Byakugan over a very long period of time causes severe eye strain, becoming unable to properly perceive targets at all. This condition, however, is not permanent