Why Do You Need Special Glasses for 3D Movies?

Many movies are created to be viewed in 3-D with the help of special glasses with colored filters. These glasses are either red and blue colored or have polarized gray lenses. When watching a special 3-D movie with these glasses, the movie appears to have depth which comes out from the screen.
 

The Basics of 3D Vision

Our 3-D vision, or depth perception, is a skill that relies on the two eyes working together to view the same object. When both of the eyes are working together, the brain can perceive depth based on the cues which create the perception of a difference in the distance from the eyes. To achieve this perception, both eyes must be focused on the same object, but the two eyes must have slightly different views of the object to create the perception of depth between the object and the eyes. 
 

How 3D Movies Create Depth

In the natural world, depth is created by objects having real size and three-dimensional characteristics. However, a movie only exists in two dimensions and must use artificial methods to create the appearance of three dimensions. The two most common methods of creating the appearance of depth are using colored tints and polarization. Using red and blue filters can create the appearance of depth by altering what aspects of the image that each eye sees. The movie is created with specific colors in places to give the appearance of depth when viewed with red and blue glasses. The glasses restrict what colors each eye can see – the red lens in the glasses prevents the red aspects of the movie from being seen and the blue lens does the opposite. Since the movie is now being viewed by both eyes but the eyes have slightly different views, there can be the appearance of depth. The other option for creating a 3-D movie is to use polarization. Polarization uses filters which restrict certain light based on the direction of the wavelength.
 
The polarized filters in polarized glasses for a 3-D movie are oriented to allow light in opposite directions to pass though the glasses. In this way, the polarized glasses work similarly to the colored glasses and create a different image for the right and left eyes when viewing the 3-D movie.
 

Problems with 3D Vision

While most people can enjoy a 3-D movie by wearing the needed glasses, there are some conditions and circumstances which can prevent the perception of depth in the movie. Any condition which prevents the eyes from working simultaneously, such as an eye turn or a lazy eye, can prevent the perception of depth in a 3-D movie. Additionally, if there is a need for prescription glasses that are not worn with the 3-D glasses, the perception may not occur as well. If while wearing the correct 3-D glasses for a 3-D movie, you are not able to perceive the three-dimensional phenomenon, consult with your eye doctor to determine if there is any eye related condition which is causing a problem.

Our eye doctor at The Optical Centre in Longmont, CO excels in prescription of glasses, contact lenses and the diagnosis of a variety of eye diseases. Call our optometrist at 303-772-6650 or schedule an eye exam appointment online if you would like to learn more about glasses for 3-D movies. Our eye doctor, Dr. Erica Whitmire provides the highest quality optometry services and eye exams in Longmont, Colorado and its surrounding areas.