Because you've ignored every single fact I've thrown at you. As I have said, Blockland is not rendered bifocally. As []----[] said, he has his own 3D glasses, and wearing them does not produce purple sight, it produces "seizure" sight. I've repeated this over and over and yet you don't stop stuffting your PURPLE all over the place.
Srsly, want me to say sorry? sorry, 3D glasses don't cause seizures, unless you have a condition in your brain where it is weak, and colors or flashes gives you seizures. It only makes the screen purple, that's it. No tricks. Just like the Night Vision Goggles, only instead of green, its purple, and the model is a 3D glasses model.