If you get a headache from 3-D pictures you probably have an eye coordination problem.
For you look-it-up people try:
Esophoria
Exophoria
Stereopsis
Depth perception
Most of the eye coordination problems that would cause this are easily corrected by some simple eye exercises you can do at home. The great majority of the time the exercises are quite simple and do not require any special equipment or office visits to the optometrist. Therefore the correction usually does not cost money---just time.
If totally corrected, you will probably stay that way because your eyes will have found a much easier way to work and good old human laziness will encourage them to work the new way. (That sentence would never get through a grammar checker. You would get a message like, "That sentence contains a bazillion words. Try to break it down into shorter sentences.").
Frequently people with this type of problem have some of the following symptoms: Skip words when reading, Repeat words when reading, Get upset stomach if tries to read in the car, Seasickness, Difficulty hitting or catching a ball. Some of the people will have only one or two of these symptoms while some people may have five or six of them...or some other symptom not mentioned.
Treating the problem is a sub-specialty of optometry or sometimes ophthalmology. Usually your best bet is to hit the Yellow Pages under "Optometrists" and look for some one who does eye exercises...perhaps they will say vision training or visual training. BEWARE there are a fair amount of people who are NOT doctors who do "Eye Exercises." There is no way that they can have a grasp on this subject, there are too many factors to learn. The docs pick up the info over 4 years of training including time in therapy clinics. There are not only special classes on the subject, but the subject is referred to in many other classes such as optics, neurology, pathology, etc.
Sorry. When I get off on a subject, I frequently forget to turn off my mouth.
Enjoy,
Jim