Now 3D technology is widely used in many areas, such as cinema, television, hospital, school and so on. When you watch 3D movies, you will be given special pair of glasses. The glasses can make the pictures out of the screen, just like they are there really around you. It will make you more exciting, especially when you see the action movies. Maybe you will ask: How does it work?
3D technology is similar to the way that the human brain and eyes work. Because the pupils (瞳孔) of a person's eyes are about 6. 5 cm apart, when we look at something, each eye sees it from a different angle (角度). Our eyes send the two pictures to our brain, and the brain puts them together. The small difference between the picture from the right eye and the picture from the left eye allows us to see depth (立体感). So a 3D movie needs two film players. One shows a left eye picture, and the other shows a right eye picture. The 3D glasses allow us to see a different picture in each eye. Without the glasses, you can't see the pictures clearly.
While one is watching 3D films, he feels that he is actually in the same environment as the things he's watching. However, it also has its disadvantages. People with eye problems may get headaches if they spend too much time watching 3D movies.
