How would you feel if your wife or mother didn't recognize you across a crowded room?
For Elaine Scheib's family, it was a reality. Scheib, who has perfectly normal vision, could not recognize the face of her husband, Bill, until they had dated for a year, and it took four years before she memorized her children's faces.
Scheib is part of the 2 percent of the population that suffers from a condition called prosopagnosia, also known as faceblindness, according to Harvard University professor Ken Nakayama, who has studied faceblindness extensively.
People with the disorder, which can lead to severe social problems, lack sufficient wiring in the part of the brain that recognizes faces. For doctors, it provides insight into how the brain functions.
"You see faces like everyone else, but when it comes time for recall there's nothing really there," said Scheib, who often recognizes people by their voice before their face.
Scheib's 14-year-old son, Toby, also is faceblind and still has trouble finding his parents in a crowd. Once, police had to be called when he and his mom became separated at an Easter egg hunt.
Bill Scheib said he recognized Toby had a problem early on. Everyone in school knew him, but he didn't know them.
The Scheibs' 16-year-old daughter, Kelsey, is not faceblind.
"They rely on me a lot [when] we go to stores. I'll be like, 'Hey mom, look who's here,'" she said, "or I'll drop hints in the conversation before they join it so they know who we're talking to."
Psychologist Brad Duchaine has made it his life's work to study the condition. He's tested hundreds of faceblind people including the Scheibs and said the parts of the brain responsible for face recognition are often far less responsive in people suffering from the condition.
To understand what faceblind people see, he said, look at the above photo of a very famous person positioned upside down. The one in 50 people who are faceblind see faces in this confusing way.
The popular name of the condition was taken from the more widespread colorblindness. "They refer to it as faceblindness because they say 'just as some people can't perceive color, I can't perceive faces normally,'" Duchaine said.
Despite the stress involved in not being able to recognize faces, the Scheibs maintain a sense of humor about it and said what matters most to them is not offending others.
"People take it personally when they are not recognized," Duchaine said. "They feel like 'I wasn't important enough for you to remember me.' So it can cause some really sticky situations."
On "Good Morning America" today, Nakayama said faceblind people just need extra clues to recognize others.
"We've all had in our lifetime a couple of moments where we don't recognize someone," he said. For faceblind people, he added, it happens every day.
They see colors and shapes the same way we do, he said. The only difference is that the faces look less distinctive.
Nakayama said faceblindness could present serious issues in the workplace, where being unable to recognize colleagues could lead to awkward misunderstandings.