According to a study carried out by UK charity The Eyecare Trust, over six million Brits have poor binocular vision, meaning they have difficulty or cannot see 3D effects in games and movies.
"It's more than you think," Dharmesh Patel, chairman of The Eyecare Trust, told MCV. "About 12 per cent have 3D vision problems and you'll find a similar percentage worldwide.
"I don't think there are any long-term negative impacts. But it can create really bad headaches and aches behind the eyes."