Both Sasuke and Madara's Sharingan awakened/evolved after they

Evolution of the Sharingan and Other Eyes: Naruto Shippuuden

why did Kurama say Sasuke is spitting image of Madara Uchiha when Izuna looks much more like him? : r/Naruto

Which Sharingan Does Itachi Have? & 9 Other Questions About His Dojutsu, Answered

Madara Stabs Sasuke! Gaara's Plan – Naruto 661

Naruto: Shippuden (season 15) - Wikipedia

What does Madara Uchiha mean when he said that Sasuke had the same 'straight comma Sharingan' as he did? - Quora

Is the Sharingan destined to die out? With sasuke and sarada only being the ones left, eventually the sarada line with dilute? Unless sasuke gets hoes? : r/Naruto

How could Sasuke not awaken his Sharingan when he saw his parents and clans killed by his brother? - Quora

How did Sasuke get the Rinnegan? Here's what you should know

Final Awaken of Sasuke? THE GOD EYES All Evolution of Sasuke's Eyes - BiliBili

Anime Anatomy: 5 Weird Secrets About Sasuke Uchiha's Body

How did Sasuke and Madara ever exist at the same time since they were both reincarnation of Indra? Did Madara still have his soul? - Quora