Although our eyes and brains are wired to desire 3d/stereo imagery, the tricks we play on our eyes and brains to cause us to see 3d when it is not really there can cause problems for some folks. See:
I believe this is true for some people. But for many of us who have watched 3d movies, create 3d images and love 3d, we just don't get dizzy nor headaches nor do we get sick to our stomachs. Instead, we enjoy the 3rd dimension trick and find it fascinating. Actually there are some people who never see 3d/stereo imagery right in front of their very eyes. It is a well known birth defect and it can be dangerous. See:
AMBLYOPIA ("lazy eye"): a visual defect that affects approximately 2 or 3 out of every 100 children in the United States. Amblyopia involves lowered visual acuity (clarity of sight) in one eye which can not be corrected by glasses or contact lenses. The result is often a loss of stereoscopic vision (3D) and depth perception. Vision therapy can improve this condition. Early detection and treatment offer the best outcome.
For many years, it was thought that amblyopia (lazy eye) was only amenable to treatment up to the age of seven or eight years. Scientific research by the National Eye Institute, National Institutes of Health, Department of Health and Human Services has now proven that effective treatment can take place up to the age of 17. Scientific research on treatment after the age of 17 has not yet been done. Nevertheless, behavioral/developmental optometrists report decades of successful treatment results with adult amblyopia patients. The length of the treatment period does increase dramatically the longer the condition has existed prior to treatment, so early detection and treatment are still preferred.
There are many reasons that early childhood eye examinations and proper treatment are essential. Research has also demonstrated that patients with amblyopia are more likely to sustain injuries resulting in the loss of their good eye than individuals with two good
So stereo/3d is not for everyone - but about 80% of the public flock to 3d movies, enjoy 3d images and it is too this audience this site is directed. If you do not like 3d/stereo imagery because it makes you dizzy or gives you headaches, you might check with an eye doctor to see if you actually have amblyopia or some other eye problem. The advantage of 3d images is that it can help folks find out that they do have a problem and get attention from a doctor.
There is also a 'trick' to viewing good 3d imagery. Unlike a 2d film or image, when you watch 3d you do not want your eyes to wander around in the image - rather keep focused on the central action the camera is trying to show you - once you try to look over to the left or right in a 3d image rather than center in on the central point the camera is wanting you to view, you might experience some side effects.