Awakening Sharingan

Those born into the Uchiha clan were cloaked in a chakra with fire attributes. But he had never before in his life experienced this kind of heat from his chakra. Still, he managed to coolly assess what was occurring within his own body.

Eyes still closed, he pushed the blankets off and sat up in his futon, before
gradually opening his eyes.
Awakening ...

The world was colored red. Everything was different from the scene of
only moments ago. On the other side of the sliding doors, three flames of
different sizes flickered. The lives of his father, mother, and Sasuke.
He focused his attention on the flames. The sliding door faded and he
could clearly see into the neighboring room. Three people lived in this red
world. If he squinted and concentrated, he felt like he would even be able to
see their hearts beating.

I’m dizzy ...
He was wasting chakra. He closed his eyes and took a deep breath. When
he slowly lifted his lids again, the world had returned to normal.
“The sharingan ...”

Book of Bright Light Chapter 2 Part 3