Dojutsu

Dōjutsu are ninja abilities that utilize the eyes, a by-product of specific kekkei genkai or kekkei mora. The word refers to both the eyes themselves, which have a number of passive abilities, and any jutsu dependent on the eyes to be performed; the former requires little to no chakra to be used, while the latter varies depending on the technique. Dōjutsu can be transplanted into others, though use of the dōjutsu is typically more limited or taxing for those without a genetic predisposition for it. While the user's eyes can be overused and dōjutsu can be prevented from being accessed for a period of time, it doesn't mean the user will be exhausted and they can still use other techniques. Of all the known dōjutsu, the Byakugan, Rinnegan, and Sharingan are collectively known as the Three Great Dōjutsu.

Byakugan
The Byakugan is the kekkei genkai that originated from the Furutani Clan, and later inherited by their distant descendants, the Ootsutsuki and Hyuuga clans. It is regarded as one of the "Three Great Dōjutsu", the others being the Sharingan and the Rinnegan.

Byaku-Sharingan
The Byaku-Sharingan is a unique dojutsu belonging to Teruko Senju and her descendants. It contains the pale white sclera of the Byakugan, but with the "copy wheel" part of the Sharingan. It tends to awaken when the user is experiencing a major emotion or in danger. Kano Ootsutsuki wanted this eye before his demise.

Jougan
The Jōgan is a unique dōjutsu that is known to the Ootsutsuki, whose members claim it's troublesome and that it's a power strongly inherited from their clan. In the manga the dōjutsu is featureless in appearance with a barely visible pupil. When depicted in the anime, the dōjutsu is blue in colour with a darkened sclera and visible pupil.

Ketsuryuugan
The Ketsuryūgan is a dōjutsu, which appears in certain individuals of the Chinoike Clan. The Ketsuryūgan is recognized by its reddish color, giving a special appearance for the users of this dōjutsu, characterized as holders of "eyes as red as blood". Its power earned it comparison to the Three Great Dōjutsu.

Mangekyou Sharingan
The Mangekyō Sharingan is an advanced form of the Sharingan that has only been activated by a handful of Uchiha. They are noted to be the "heavenly eyes that see the truth of all of creation without obstruction."

Rinnegan
The Rinnegan is reputed as the most exalted eye amongst the "Three Great Dōjutsu", the others being the Byakugan and Sharingan. It is said that in times of disorder, one who wields the Rinnegan is sent down from the heavens to become either a "God of Creation" who will calm the world or a "Destroyer" who will reduce everything to nothingness. The Rinnegan is characterized by a ripple pattern that spreads over the eyeball.

Sharingan
The Sharingan is the dōjutsu kekkei genkai of the Uchiha clan that appears selectively among its members. It is regarded as one of the "Three Great Dōjutsu", the others being the Byakugan and the Rinnegan.

Tenseigan
The Tenseigan is a dōjutsu introduced in The Last: Naruto the Movie. The movie's novelization explains that the Tenseigan can be acquired when an Ootsutsuki is implanted with the Byakugan of a Hyuuga: this combination of the two clans' chakra transforms the Byakugan into Tenseigan.

Chijagan
The Chijagan is Furostomi Chinoike's ocular power. Orochimaru gave her this unique dojutsu accidentally, by many years of experimentation on her Ketsuryuugan and her DNA. The mix of sage chakra and her own also influenced this dojutsu's manifestation.

Trivia

 * Masashi Kishimoto has stated that if a Sharingan user and a Byakugan user were to have a child, their offspring would have one Byakugan and one Sharingan, but under certain circumstances, the child will have a Byaku-Sharingan, suggesting that reintroducing Ootsutsuki blood will help the Byaku-Sharingan manifest.
 * The Totoi clan's dojutsu, the Bokyakugan, literally means "Oblivion Eye" due to the user being oblivious to what is happening around them (the dojutsu feels like needles gouging your eyeball if overused) or the user plunges society into the depths of oblivion (darkness).