The 3Ds of Stereoscopic 3D Viewing Problems: An Introduction

There are three principal “Ds” of stereoscopic 3D viewing problems:

• Discomfort
• Dizziness
• Lack of Depth

Let’s look at each factor, though space does not permit an in-depth view here.  My purpose is to raise awareness of visual issues that have surfaced with the popularity of 3D movies, and the emergence of 3D media viewing.

Discomfort

The most active researcher in the optometric field is Martin Banks at UC Berkeley College of Optometry.  Banks and his group have identified “vergence-accommodation conflict”, the discrepancy between the plane of the screen, and the convergence angle.  The essence of the conflict is that vergence and accommodation are not in the same plane, and this is minimized by having the patient positioned relatively far from the screen, where accommodation is minimally active, and centered with the action.  Banks has a nice powerpoint slide showing the “value” of a seat in a movie theater in terms of minimizing the viewing conflict.

3D BANKS – Where to Sit in Theatre

It’s worth noting here that the field of behavioral optometry is heavily predicated on visual stress that ensues from the mismatch between vergence and accommodation not being positioned at the same viewing plane.   Forrest and Birnbaum, have written extensively on this subject, with implications for imbalance in the sympathetic and parasympathetic nervous systems.  More on that another day.

Dizziness

This is an intriguing symptom, and is likely tied in to the nature of the virtual reality environment causing vergence-accommodation conflict.  Beyond this, Kenneth Ciuffreda, an optometric researcher at SUNY College of Optometry, has identified that visual-vestibular imbalances can be exacerbated by the stereoscopic 3D viewing environment.

Dr. Ciuffreda’s work supports the clinical perspectives of Dr. Roderic Gillian, an optometrist who coined the term “See Sick Syndrome” in the 1970s and 1980s for neuro-optometric vestibular dysfunction.  Pacific University College of Optometry (PUCO) designed CE coursework based on this concept.

So in susceptible patients we have a double whammy of sorts:  Stereoscopic 3D movies exaggerate visual motion hypersensitivity (VMH) causing motion sickness, and vergence-accommodation conflict exaggerates the sensory mismatch, further exacerbating VMH.

Lack of Depth

The last “D” is obvious, but it won’t result in any symptom and is therefore a relatively silent problem.  Silent in the sense that the viewer will be disappointed in the viewing experience, but not think much of it.  The real message here is that if the media presentations increasingly rely on the 3D experience, lack of appreciation of the extra dimension actually serves as a screening tool of sorts that the view has a type of binocular vision problem.

In Part 2, we’ll take a look at some fascinating insights on the 3Ds from the Schubin Cafe, and how Schubin’s perspectives may help revolutionize patient care.