3D is the new "it" feature for HDTVs, from ultra-high-end displays to more affordable sets in the $1,000 price range. Since the consumer launch of 3D HDTVs, the reception has been somewhat lukewarm. Consumers aren't too keen on the idea of wearing glasses to view 3D content outside of their local multiplexes. They don't necessarily want to buy all new equipment, such as Blu-ray players and/or 3D-capable receivers, both of which drive the cost of 3D skyward. Finally, many consumers are simply underwhelmed by the selection of 3D movies available, be they on Blu-ray or via their cable or satellite providers. Panasonic, Sony, DirecTV and Comcast are certainly trying to push 3D but it's been a fairly slow roll, which is shocking given how much credence the 3D format has been given by the studios at the theatrical level. Consumer objections aside, another troubling development for 3D centers around the physical reaction that people often have when watching 3D.
• Read about possible glasses-free solutions to 3D HDTV.
As a physician and eye surgeon, it's important to know how 3D works - specifically as it relates to your eyes. To start, someone who wants to experience 3D must have sharp eyesight in both eyes and have excellent coordination and alignment of those two eyes. In other words, having 20/20 vision in both eyes and having perfect eye alignment without "crossed-in" or "wandering out" eyes will enable you to have the highest level of depth perception needed to enjoy the best of 3D. Clearly, not everyone has perfect eyesight. Before the days of 3D HDTV you didn't need excellent vision to enjoy 1080p video in 2D. 3D is a much more complicated proposition for your eyes if you want to be truly immersed in the video experience.
Just as people have different levels of vision, people have different levels of 3D vision. The lowest levels of 3D vision involve depth perception due to what scientists refer to as "image size and image overlap." For example, with image size, the actual object's size relative to another object gives clues about nearness. A larger object appears closer and a small object appears farther away. Of course, that is not always the case. For example if a mouse is standing a foot away, it is still smaller than an elephant ten feet away. But if you look closely at the mouse, its outline will overlap the elephant and thus you can tell that it is in front of the elephant due to image overlap. These two kinds of depth perception can be appreciated with only one eye with average vision. In fact, this is the primary way we perceive depth when watching 2D HDTV.