Why do 3-D glasses cause illusion of depth?

3-D glasses are based on a technique called stereoscopic imaging, in which 2-D images are combined to create an illusion of depth.

Most of you don't know about 3-D glass, however, the fact that this type of glass has been around since the 1920s, and became especially popular in the 1950s. use, though not as popular as before.

3-D glasses are based on a technique called stereoscopic imaging, in which 2-D images are combined to create an illusion of depth. However, with this technique, we need to have binocular vision.

Humans are one of the few species on Earth with binocular vision. Binocular vision is the ability to use two eyes at the same time to observe an object.

The binocular vision has the following four advantages: first, in case one eye is damaged, the other eye can still operate almost when the eyes are intact; second, the scope of observation in the human eye is much greater than that of animals without eyesight; thirdly, binocular vision increases the ability to observe fuzzy objects; and fourth, because there is a distance between the human eye and the same area of ​​the skull, the binocular vision helps the brain receive the correct depth.

3-D technology exploits the advantages of binocular vision by introducing two slightly different images in each eye, aiming to create an illusion in depth perception. Although we may not pay attention to this every day, each of our eyes actually looks at different images.

Try observing an object when you close your right eye, then remain still, open your right eye and close your left eye. You will find that even though you are not moving, the object seems to have moved a little to the right or to the left, depending on which eye you aim for, which eye is open. This gives us the ability to accurately estimate distance to an object - depth perception.

Another way through which 3-D glasses can cause depth hallucinations and project 2 different images into each eye helps us take advantage of one of the sensations we know, That is the color. In this case, the system will project two images: one red and one blue. In this order, this means that 3-D glasses must have a red eye filter and a blue filter for the other eye. The next two images will be processed by the brain, which will deceive our thinking that this image has depth, while in fact it is projected on a 2-D screen.

Another method to create the illusion of depth is to use polarized prisms. Polarization is a property of electromagnetic waves expressed through the preferred oscillation direction for electrical equipment. The human eye cannot distinguish between different polarized light, but with appropriate clicks, this is possible. As in the case of the preceding description method, two images are projected onto a screen, however in this method each image has a different polarity.