US ophthalmology experts at Northwestern University Feinberg School of Medicine in Chicago are warning that watching 3D films may lead to viewers experiencing headaches.

Reuters reports that ophthalmology professor Dr Michael Rosenberg is warning film buffs to get their eyesight checked before watching 3D films, as for some people with eye problems, the experience could lead to a ‘3D headache’.

Dr Rosenburg told Reuters:

‘There are a lot of people walking around with very minor eye problems – for example a minor muscle imbalance, which under normal circumstances the brain deals with naturally.’

He said that the new experience of watching 3D films for prolonged periods could result in ‘greater mental effort’, leading to an aching head.

Dr Deborah Friedman – professor of ophthalmology and neurology at the University of Rochester Medical Center in New York – said that in normal vision, each eye sees objects at a slightly different angle, which naturally creates a perception of depth in the brain.

However, in 3D films, the images are not ‘calibrated’ in the same way as they would be by the eyes and brain.

‘If your eyes are a little off to begin with, then it's really “throwing” a whole degree of effort that your brain now needs to exert,’ said Dr Friedman. ‘This disparity for some people will give them a headache.’

There are currently no studies into the effect of 3D films on headaches, said a spokesman for RealD – a company that provides 3D equipment to theatres. Rick Heineman said that headaches and nausea were the chief reasons 3D technology never took off.

However, he added that, previously, 3D technology employed two film projectors to project a left eye image and a right eye image. Mr Heineman said that the 3D glasses provided allowed viewers to see the different images produced in both eyes.

‘People often complained of headaches and it was really because the projectors weren't lined up. By going to a single digital projector, those issues were solved,’ he added.

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