Harryhausen admired the three-dimensional quality of modern digital effects, but he still preferred the old-fashioned way of creating fantasy.

NPR: Special Effects Master Ray Harryhausen Dies At 92

The warning follows many others on the potential health effects of three-dimensional entertainment.

CNN: John D. Sutter

But researchers at the Centre for the Developing Brain have found ways to counter the effects of these movements, building up full three-dimensional pictures while the foetus is in motion.

BBC: Babies' brains to be mapped in the womb and after birth