Thanks for all replies.

1. Smart Glass is not suitable as it is too expensive
2. Tinted is not suitable as mentioned by Kintos, at night the source of light will came from my room, someone from outside will be able to see you in the room.
3. I have curtain but it will blocked all my wind.
4. Blind is my last resort as it is not cheap due to the hexagon type from my window.

Or else i just close my curtain at night