Passive 3D glasses are a type of eyewear used to view 3D content, such as movies or video games. They work by filtering images displayed on a screen, allowing each eye to see a different image. This creates the illusion of depth, making the viewing experience more immersive. Passive glasses are typically lightweight and inexpensive, making them popular in cinemas. These glasses use polarized lenses, which means they have special coatings that block certain light waves. This technology is different from active 3D glasses, which require batteries and electronic components. Passive 3D glasses are often used in conjunction with polarized screens to enhance the viewing experience.