it's a genetic eye technique that naturally occurs in members of the Uchiha clan
He wasn't born with Sharingans. He collect Sharingans from the Uchiha Massacre and by the help of Orochimaru he implanted Sharingans in his hand and one eye along with First hokage cell for chakra.
Use lenses or photoshop
The same as all Sharingans
Hel will have 2 his own and Itachi's
LOL ... NONE... if you want to have sharingan then buy contact lens in the market...
take out the eyes of another sharingan user then take yours out and replace with the others
yes he does because after the battle with naruto and sasuke he laughs and his eyes change into all the sharingans
He Got it From Obito when he was on a mission when he was younger. Obito got crushed by a rock and gave kakashi his Sharingan as a gift before he died. Obito had the Sharingan because he was an Uchiha.
Quite a few things. Mengenkyou sharingans are EXTREMELY POWERFUL Three different mengenkyou sharingans sealed a demon that created the uchiha clan, and those three users could possibly re-aweken said demon. Also, there are four. Uchiha Madara (Tobi) has one, Itachi (dead) has one ( in his death he gives his powers to Sasuke apparently) and Kakashi has one in his one eye. So technically there are four users.
obviously the rinnengan which was used by the sage of six paths. he was the only one to have it. Peins rinnengan was modified/altered so it isn't the real deal. Or the strongest one can be the chibis eye if you count that. it is made of lots of sharingans and rinnengans
There are many different kinds of sharingan.they are(1st slump,2nd slump,3rd slump,mangekyo form 1,mangekyo form 2,hawkeye sharingan,and internal sharingan.)
Over-use of sharingan techniques will eventually cause blindness, rendering the eye's power useless. To prevent this, the user needs to replace his eyes with someone else's, giving him Eternal Mangekyo Sharingan, which do not suffer the same issue.