Question

He unfocused his eyes from his screen and turned around to face me, responding only with a gently growing smirk.
I blindly searched for the light switch in the obscurity of the room. As my hands came upon the plastic knob, I quickly flicked it on and was immediately blinded once again by the sudden flash of brightness. After my vision restored, I was able get a better look at the place.
His whole room was teeming with books and stacks of papers. He looked at me annoyingly and I responded with a mocking smirk.

Is this sentence correctly written? Are there any grammatical/punctation errors?