The primary type of glasses used for 3D movies in the United States is the passive polarized 3D glasses. These glasses are lightweight, comfortable, and cost-effective, making them the standard choice for most theaters. The technology behind these glasses involves polarized lenses that filter light in a way that creates the illusion of depth when viewed through a 3D projector.

Passive polarized 3D glasses are preferred due to their simplicity and affordability. They are reusable and do not require any power source, making them convenient for both theaters and consumers. According to a report by Grand View Research, the global 3D glasses market size was valued at USD 1.6 billion in 2020 and is expected to grow at a CAGR of 6.1% from 2021 to 2028. This growth is attributed to the increasing popularity of 3D movies and the growing demand for immersive entertainment experiences.

The use of passive polarized 3D glasses is also widespread due to their compatibility with a wide range of 3D formats. They work with both film-based and digital 3D formats, making them versatile for different types of screenings. Additionally, these glasses are safe for children and adults alike, as they do not emit any harmful radiation.

While passive polarized 3D glasses are the most common, there are other types of 3D glasses used in specific circumstances. Active shutter 3D glasses, for example, are used in home theaters and some movie theaters. These glasses use battery-powered shutters that open and close in sync with the 3D projector, creating a more immersive experience. However, they are more expensive and less comfortable for extended wear compared to passive polarized glasses.

In conclusion, passive polarized 3D glasses are the standard choice for 3D movie experiences in the United States due to their affordability, comfort, and compatibility with various 3D formats. The growing demand for immersive entertainment and the increasing popularity of 3D movies are driving the market for these glasses, with a projected growth rate of 6.1% from 2021 to 2028.