3 kinds of Doujutsu/Eye Technique
1.) Byakugan - White Eye (Hyuuga Clan)

Byakugan is the blood inheritance limit of the Hyuuga Clan. The Hyuuga clan was one of the founding noble families of Leaf village. The clan itself is said to be the ancestors of the Uchiha clan who possess the bloodline of the Sharingan eye. When the "Byakugan" is activated, the clan member gains an extra-sensory perception, which gives them penetrating sight and telescopic vision. This allows them to see the tenketsu; the internal chakra coils system 361 pressure points. This vision also grants the member a near 360° view of their surroundings, the higher the skill of the clan member, the further the distance from which they can sense incoming attacks. Unfortunately the vision does have a weakness, a small blind spot that extends outwards from the vertebra of the upper back.
2.) Mangekyou Sharingan - Kaleidoscope Copying Wheel Eye (Uchiha Clan)
Sharingan is the blood inheritance limit of the Uchiha Clan. The Mangekyou Sharingan is a legendary doujutsu ability which has only emerged in a few clan members in its history. There is still mystery surrounding the eye and the Uchiha clan itself. Each user develops their own unique looking Mangekyou. The requirements for gaining the Mangekyou are very controversial in nature. After Uchiha Itachi murdered his best friend Shisui he gained Mangekyou. He told his younger brother Sasuke that to gain the Mangekyou, he too would have to kill his closest friend. Itachi told Sasuke that a scroll in their clan shrine revealed the true original purpose of the clan doujutsu. This scroll and Itachi himself revealed that the former leader of their clan, Uchiha Madara and his younger brother were the first to obtain Mangekyou. Unlike Itachi though, they apparently did not have to kill their best friend to obtain it, merely the competition between them allowed it to develop.
3.) Rinnegan - Transmigration Eye

Rinnegan is the blood inheritance limit of Rokudou Sennin (Six Realms Sage) and his descendants. Rokudou Sennin was viewed as the original shinobi and his Doujutsu was regarded as the most venerable of the three great Doujutsu. As the original shinobi it was said he created modern Ninjutsu. The Rinnegan was regarded as a god of creation when the world was racked with chaos and as a weapon of destruction which could return everything to nothingness. Usage of the Rinnegan was said to give the user mastery over all six forms of chakra nature manipulation.
