Beware: 3D hazards

By Yoon Ja-young

Cha Young-hee, a housewife living in Busan, decided that she would never again watch a three-dimensional (3D) animation at movie theaters. “I felt dizzy for about an hour after watching it. I felt more tired than ever,” she said.

3D has become the buzzword in TV broadcasting and theaters, but more than a few people are still complaining of the uncomfortable feeling after watching 3D contents.

Consequently, the Korea Research Institute of Standards and Science (KRISS) is set to conduct research on how 3D TV watching affects the human body amid growing concerns.

Dizziness after watching 3D contents

Each of our two pupils, which are separated by a distance of 6 centimeters, get different images. They are combined in the brain to provide depth perception.

3D images work in a similar way. A special camera, which has two lenses like a pair of human eyes, captures images from two different angles that are shown on the screen at once. Viewers get the sense of depth when they look at these images separately with special glasses.

However, viewers often complain of an uncomfortable feeling, such as dizziness, headaches, or eye fatigue. The Korea Communications Commission last year conducted a survey on 150 people who watched 3D TV for between 15 and 30 minutes from a distance of about 3 meters and found over 34 percent of them suffered from dizziness. Nearly 23 percent complained of seeing double images, and half of them complained of symptoms like eye fatigue or simply discomfort from wearing 3D glasses.

“3D technology deceives the human eyes to create a sense of depth even while watching something two-dimensional. This definitely would have some effect on the human body,” said Park Se-jin, Ph. D, who is leading the research project on 3D TV at the KRISS. The vestibular organ in the ear interacts with the eyes and other nerve system to realize a sense of balance, and people feel dizzy when they are exposed to a peculiar environment.

For instance, when people ride on a rollercoaster, they feel dizzy as the brain gets confused with the eyes following rapidly changing scenes while the body remains seated. 3D contents also interfere with our sense of balance.

Park pointed out that 3D products were released in the market without much research on how they affect the human body. “There have been some research conducted in other countries, but Korea has done only scant research on the subject.”

Looking for the ideal 3D

The research team led by Park will test 250 people from a wide range of age groups, who will watch ordinary TV and 3D TV to check the effect on the human body, such as brainwaves, heartbeat, eye fatigue, stress, electric resistance of the skin and body temperature. The research will begin next week for two months.

“The perception of 3D TV differs considerably depending on the viewer. Its effect varies between senior citizens and children and men and women. To develop a 3D TV that suits everyone, accumulating solid data is essential,” he said.

A sense of depth varies depending on the angle between the two cameras, and likewise, the distance between the two pupils affects how a person watches 3D TV. Contents producers, such as 3D movie directors, can also benefit from the data.

“When you film a 2D movie, shooting a tree up close to the camera, the island in the middle, and the horizon far away in the same shot will create a beautiful scene. In 3D movies, however, the tree up close causes discomfort for the eyes,” Park explained. The research will accumulate data on what makes 3D viewers uncomfortable and which conditions should be improved for comfortable 3D TV viewing.

The dizziness accompanying 3D TV watching intensified overheated disputes between Samsung and LG over their 3D TV technologies earlier this year.

LG, which chose to pursue the passive film pattern retarder (FPR) 3D technology, said it is easier on the eyes than Samsung’s shutter glass method as the former flickers less while Samsung boasts of higher definition.

Meanwhile the Korea Communications Commission has announced a guideline for 3D contents viewers. It recommends that people watch 3D contents at distances equaling two to six times the vertical length of the 3D screen. Those who suffer from motion sickness should take extra precaution as it is likely to be more distressing for them. Those with narrow gaps between their eyes may feel the effects more severely than others as well.

Viewers should take a rest for five to 15 minutes after an hour of watching and they should refrain from watching 3D contents when they are tired.