A highlight of my Christmas trip to New York last year was that I saw the movie 'Avatar', not only in 3D but also in an IMAX theatre. This was my introduction to 3D and with a screen towering over me I really did feel like I was in that moon jungle on mythical Pandora.

Reflexively I ducked and dodged in my seat to avoid hanging tree branches, giant birdlike toruks, and war machines.

In the ladies room after the film, a few women said they felt ill. One woman said she felt so seasick that she almost had to leave the theatre to calm her stomach. I had some impairment with my footing. I wasn't exactly dizzy but I had some difficulty understanding exactly where the ground was. I took it easy leaving the cinema and 30 minutes later felt normal again.

It didn't feel dangerous to me but the electronic manufacturing giant Samsung, issued a health warning on watching 3D TV a few months ago. According to a statement on the company website, 3D viewing can trigger epilepsy and even strokes.

"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 suffer from, or have a family history of epilepsy or strokes, please consult with a medical specialist before using the 3D function.

"Even those without a personal or family history of epilepsy or stroke may have an undiagnosed condition that can cause photosensitive epileptic seizures," the statement said.

M&M International has the largest selection of televisions on the Island. Manager Matthew Mello showed me three 3D sets. He was aware of the 3D warning issued by Samsung, but said most residents are not buying those TVs for their 3D capability. He said it just so happens that the sets with best picture quality also happen to have the 3D feature.

According to Mr. Mello most people don't use the feature. And he explained that the feature works best when the source is 3D. The sets do a simulated 3D, where the two dimensional images are converted to 3D, but it's subtle and nothing like the 3D you see in movie theatres.

In fact, he pointed out that, only three movies are currently available in true 3D for home use.

Catherine Prendiville, ophthalmologist and associate specialist with Bermuda International Eye Institute, said there's been no hard evidence to show that viewing 3D movies and 3D TV causes any damage to the eyes.

She said the technology used to create the 3D effect causes the eye muscles and brain to work differently than they do when seeing actual three-dimensional images.

She said eyestrain and headaches often result.

"People will complain that their eyes feel tired and sore, and that's because of the disparity in the projected images used to create the 3D effect," she said.

Dr. Prendiville also noted that about 20 percent of the population would be unable to experience 3D movie and TV effects because they have low vision and/or cataracts. And she said another eight percent do not have accurate depth perception.

3D is all about showing flat images in such a way that they appear to have depth. People who have a deficit in this area are thus unlikely to be able to fully experience the 3D imagery.

Although it can cause headaches and eyestrain Dr. Prendiville said she would not advise against watching 3D films or TV nor would she recommend imposing time limits to such viewing.

But Samsung was strong in its release, which said that 3D viewing posed a greater health risk to children and teenagers. The manufacturer advised that these groups be closely supervised when viewing 3D digital content and that parents or guardians ask them how they are feeling while they are viewing.

A salesperson on the floor at local retailer PTech, said 3D TVs would be in stock for Christmas. He said he had heard that persons should not drink alcohol while watching them but was unaware of any other potential health hazards.

It may sound comical but it's in the Samsung warning: "Pregnant women, the elderly, sufferers of serious medical conditions, those who are sleep deprived or under the influence of alcohol should avoid utilising the unit's 3D functionality."

The warning also recommends viewers to immediately stop watching 3D content and consult their physician if they experience any of the following symptoms: altered vision, lightheadedness, dizziness, involuntary movements such as eye or muscle twitching, confusion, nausea, convulsions, cramps or disorientation.

The manufacturer suggests frequent breaks when watching 3D content to lessen the effects of eye strain, motion sickness, perceptual after effects, disorientation, and decreased postural stability.

The advice also read: "If your eyes show signs of fatigue or dryness or if you have any of the above symptoms, immediately discontinue use of this device and do not resume using it for at least 30 minutes after the symptoms have subsided."

While this can work fine if you are watching TV, it is inconvenient if you are at a movie theatre. The projectionist at Liberty Theatre said the company has not received any complaints of customers feeling ill or uncomfortable watching 3D movies in their cinemas.

He said sometimes immediately after 3D films people would say their eyes felt sore or strained. "But after a few minutes they feel better," he said. "It's just a bit of getting their eyes to adjust back to normal."

Shandon Easton, owner of Specialty Cinema, said the 3D technology has been in cinemas for six years. He said only people who suffer with migraines or have vision problems have difficulty seeing 3D films shown in his theatre.

"Pretty much all the kinks have been worked out for viewing and people rarely get headaches watching 3D in theatres," he said.

But Mr. Easton said problems do exist in the technology for TV and home use. "I don't suffer with headaches at all and even I got terrible headaches watching presentations at a conference I went to recently," he said.

According to him headaches and other side effects largely come about when images jump out of the screen at you.

"Your brain cannot handle that stimulation for more than a few minutes," he said. "That's what triggers the headaches."

In his view the industry will have more of those types of images in the home formats in an effort to be more marketable.

"That will be what we will have to watch out for. That's what will make us feel dizzy and get headaches," he said.

To see the full Samsung warning visit the following webpage: www.samsung.com/au/tv/12th_April_old_files/warning.html