3D glasses are not singular, there are also many different kinds in the market, with a wide range of prices. However, among the current 3D glasses, red-blue glasses can be considered the most popular.
The popularity of this type of glasses is largely related to its price. Nowadays, we mostly use 3D glasses in the cinema for watching 3D movies and may not use them much during regular times. Therefore, if a pair of 3D glasses is too expensive, it would be quite hard to accept. Red-blue glasses are considered to be the most cost-effective type of 3D glasses, with prices possibly under 100 yuan.
For instance, the red-blue glasses on AiDai website, branded as "YiShiJie", only cost 35 yuan. It can be said to be very affordable.
Red-blue glasses are also very fashionable in appearance.