How to get rid of the cat's eye on the security door

1. If it is a cat's eye with a threaded mouth, we can screw it on both sides of the door at the same time, and screw it in the opposite direction to remove it.

2. Our door can also screw the inner ring directly into the cat's eye, which requires a little force. You can pull it out directly counterclockwise until it is very loose.

3. The cat's eye has two layers, the inner layer is concave mirror and the outer layer is convex lens. Lenses can change the angle of light. When we look out from the door, the outdoor image just falls on the lens because of the lens, and finally we get a more enlarged image; On the contrary, from the outside to the inside of the door, because the focal length of the lens is very short, it falls between the two lenses in the cat's eye, so it is impossible to image and see the room clearly.