The health risks posed by watching 3D TVs have been dismissed by visual perception authority Professor Colin Clifford a few days ago, who said that viewing 3D content on a 3D TV does not pose more threat to your eyes and your brains than watching a more conventional 2D TV provided that you are sensible about the time spent and your viewing distance from the TV screen.
However, some medical experts in the field of eyecare have different views from Professor Clifford on this matter. Professor Steven Nusinowitz, who is an assistant professor of ophthalmology at the Jules Stein Eye Institute in the University of California, Los Angeles, said that the way 3D images are presented by 3D displays, and then interpreted by the brain can cause cause some people to suffer from sickness due to disconnection between what your eyes see and your body is actually experiencing.
Assistant Professor Nusinowitz explained that in the current 3D TV format, 2 slightly different images of the same scene are presented to each eye separately through a pair of 3D glasses coated with polarised filter. The brain then merges these two images to create an illusion of 3D depth. He went on to give 2 examples of how disorientation can occur for some viewers.
The first is when an object is moving towards you in real life. To maintain focus on the object, your pupils would have to converge towards each other, and your lenses would have to change their shapes in a process known medically as “accommodation”. But when watching objects moving closer to you in a 3D movie, your eyes are working hard to fuse the images rather than accommodate, which can be somewhat disorientating.
Another example is how you could be fed with realistic impressions that you are moving in a particular scene when watching a 3D film, but your own vestibular system (the sensory system in your body which gives you feedback on balance and spatial orientation) is telling your brain that you are in fact static. Some people may feel sick with this disparity, said Assistant Professor Nusinowitz.
Dr Lisa Park, clinical assistant professor in the department of ophthalmology at the Langone Medical Center in New York University, also voiced concerns over the potential side effects of watching 3D TV. Because of the way 3D content demands the eyes to move in an unnatural manner, she said that symptoms of headache, sickness and tiredness might ensue.