After wrapping up the latest Pirates of the Carribean flick, you might think the cast would have leapt at the chance to gawp at the final edited flick in all its 3D glory. After all, watching a piratey Al Swearengen blasting cannon balls over your heads, or seeing Captain Jack Sparrow's leering face lean into the audience with a wink, ought to make for an immersive and exciting film experience, even if the film itself is a bag of warm plop. There's just one problem – the film's main star, Johnny Depp, can't see the 3D effect.
'I’m unable to see in 3D,' Depp recently told Access Hollywood. 'I can’t – my eyes don’t see in 3D. I have a weird eye.' Depp is one of millions of other people in the world who can't take part in the supposed 3D revolution, to the point where he can't even see the killer feature of the films in which he stars.
I'm also one of them. I have what's known as Amblyopia, otherwise known as lazy eye, which in my case means it's hard for me to put two images together to form a single image and see the 3D effect. I can usually see a stereoscopic 3D image for a few minutes when I focus my eyes, but then it subsides when I relax. For others, the effects can be worse. Some can't see the 3D effect at all, while some complain of dizziness, migraines, headaches and nausea.
I can't see 3D. I've got weird eyes
Although the principles of stereoscopic 3D have been around for a long time, it's only in the last couple of years that it's really been taken seriously by TV manufacturers, movie makers and game developers. As such, there hasn't yet been any large-scale research into the long-term effects, and there are also no solid figures to show exactly how many people struggle with seeing the stereoscopic 3D effect yet. You can get a rough idea of the numbers, however.
The Eyecare Trust in the UK says that around 12 per cent of people in the UK will struggle to see the effect, based on records of patients with appropriate symptoms. Meanwhile, the American Optometric Association (AOA) claims that research shows that 56 per cent of people aged between 18 and 38 in US have a problem relating to binocular vision.
The AOA's Eye-Q survey of over 1,000 people in the US also revealed that, among people who had problems viewing 3D, 13 per cent experienced headaches, 12 per cent experienced blurred vision and 11 per cent experienced dizziness as a result of viewing 3D.
For someone like me, 3D is like Magic Eye all over again, where posters and books covered with colourful pixels would supposedly reveal a further picture hidden in the image if you stared at it in the correct way. Unless you had a lazy eye, of course, in which case your Magic Eye poster was basically a colourful barcode collage. However, more people should be able to see stereoscopic 3D than Magic Eye.
'Magic Eye is different to the 3D we have now,' says the Association of Optometrists' education advisor, Karen Sparrow. 'Actually, someone without lazy eye – someone with very good vision in their right eye and left eye – may not be able to see Magic Eye, because you have to dissociate your eyes and make them effectively wander ever so slightly, so you're focusing in front of the image or behind the image. It's a slightly different effect, but if you have a lazy eye you can't see Magic Eye either, as well as not being able to easily see 3D.'
Oh look, it's a sail boat!
So what causes lazy eye? 'Basically, it means your eye didn't develop at a very young age,' says Sparrow, 'and you'll generally have two eyes that are of different prescriptions. As the visual system develops, a child's brain says: "well, that's a bit blurry, I'll ignore than and concentrate on the clear image," and therefore the visual system develops in a way that scrambles the message.'
Unless this is detected early-on in childhood, when the eye is still developing (ideally before you're eight years old), then you've got no chance of fixing it either, whether you correct the blurriness in one eye or not.
'Even if you give the weaker eye a clearer image later on,' says Sparrow, 'the message is already scrambled, and it can't be unscrambled. The way our vision works isn't just what our eyes receive; it's also how our brains interpret it. It's like having a lead between your digital camera and your PC. The digital camera might have a great picture on it, but if that lead doesn't send the picture to your PC properly then you're never going to get a proper clear picture on your PC.'
Lazy eye isn't the only condition that can prevent people from seeing 3D, though. If you're colour blind, then old-school red-green 3D probably isn't going to work for you either, as red and green are typically the colours that are indistinguishable if you're colour blind, often being only visible as brown.