The Korean electronic giant, Samsung, has issued a warning about possible precipitation of seizures and other medical problems by 3D TV viewing in susceptible individuals. Their photosensitive seizure warning reads (from http://www.samsung.com/au/tv/warning.html )

• 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. 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.
• If you experience any of the following symptoms, 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. Parents should monitor and ask their children about the above symptoms as children and teenagers may be more likely to experience these symptoms than adults.

How much of a potential problem this is remains unknown, because 3D technology is new and no studies of 3D viewing in photosensitive individuals have yet been published. More than one type of 3D technology is in use, and risks might differ depending upon the technology. The Samsung TV uses electronically controlled rapidly alternating eye viewing, which might produce a flicker effect. Under some circumstances, flicker can provoke seizures. The movie Avatar uses a different technology of circularly polarized light, viewed with non-electronic polarized eyeglasses. Some individuals have reported seizures during or after watching Avatar. However, with millions of viewers watching for time periods of several hours each, some medical events will occur by chance during or after the viewing.

Until more is known about 3D viewing and seizures, people with epilepsy should be aware that there might be a problem, but more time and research will be needed to know whether a significant problem exists. Individual accounts of 3D experiences can be found in the Community Forum section of epilepsy.com, and an article on the general issue of photosensitivity (not relating specifically to 3D) can be found at http://www.epilepsy.com/epilepsy/newsletter_photosensitive_seizures.