Imagine seeing the world and everything in it as flat.

The distance between your car and the one in front of you is difficult, if not impossible, to gauge.

That's the two dimensional world Cindy Monter lived in, until now.

"In 2D, I'd see shadows and I wouldn't know how big you are, because you'd look totally flat," said Monter.

"Her brain wants to use both eyes at the same time," said Carl Hillier, O.D., FCOVD, San Diego Center for Vision Care.

According to Hillier, the 50-year old Monter was told she'd never be able to see in 3D. He helped her change that prediction using vision therapy.

Vision therapy consists of exercises designed to improve vision by training the entire visual system, eyes, brain, body, to change the way they work.

Walking to a meter while reading or drawing circles outside of her field of vision helped retrained Monter's brain to see the way most of us do.

"It's a wild experience getting 3D vision after never having it," said Monter. "After 6 months I had acquired 3D vision and I had no idea what I had. I thought I had the flu for a week."

"Vision really occurs in the brain it doesn't really occur in the eye," explained Dr. Hillier.

The therapy doesn't work for everyone but Monter advises others with 2D vision to investigate the possibilities.

"Even if you're over 40, who cares?" said Monter. "If it improves the quality of life as much as it's improved mine then it's worth a try."