Pregnant women, drunk people and those who have a history of epilepsy or stroke, should not watch 3-D television because of potential health issues, electronics manufacturer Samsung says on its Web site. Some viewers may experience an epileptic seizure or stroke when exposed to certain flashing images or lights contained in certain television pictures or video games, Samsung's warning message says. "If you or any of your family has a history of epilepsy or stroke, please consult with a medical specialist before using the 3D function."

Viewers who may experience any of the following symptoms, should immediately stop watching 3D pictures and consult a medical specialist: (1) altered vision; (2) lightheadedness; (3) dizziness; (4) involuntary movements such as eye or muscle twitching; (5) confusion; (6) nausea; (7) loss of awareness; (8) convulsions; (9) cramps; and/or (10) disorientation.

Viewing in 3D mode may also cause motion sickness, perceptual after effects, disorientation, eye strain, and decreased postural stability, Samsung added. The company recommendeds that users take frequent breaks to lessen the likelihood of these effects.

Samsung also does not recommend watching 3D if you are in bad physical condition, need sleep or have been drinking alcohol. In addition, watching TV while wearing 3D Active Glasses for an extended period of time may cause headaches or fatigue, Samsung says.

The ideal viewing distance from a 3D Display should be at least three times the height of the TV screen.

The TV maker also says wearing its 3-D glasses in normal situations, when you're not watching 3-D TV, "may be physically harmful to you and may weaken your eyesight."

Samsung and Panasonic began selling the first 3-D TVs in the U.S. last month.

Manu manufacturers including Sony, Toshiba and LG are set to debut 3-D home entertainment systems this year. When watching 3-D TV, users wear special 3D Active Glasses with lenses that open and close rapidly to produce an image that appears to leap off of the screen.