For someone with normal vision, putting on the gray plastic headgear is a little like stepping through the tube and into the slightly fuzzy, black-and-white world of "The Honeymooners," or some other 1950s-era television show.
But for some of the 2.5 million Americans with poor eyesight that can't be corrected by conventional glasses or other treatments, the video goggles unveiled yesterday by Johns Hopkins researchers and NASA could be a liberating experience, doctors say.
The goggles could give some people the ability to cook and clean for themselves, shop, read a newspaper, go bowling or even recognize loved ones -- all by watching tiny televisions mounted inches from their eyes.
"You are literally watching the world on television -- I know most Americans are accused of doing that anyway," Dr. Robert W. Massof, director of the Wilmer Eye Institute's Lions Vision Center, said at a news conference yesterday.
Testing of the eyegear is expected to begin at the Baltimore and Fort Howard veterans' hospitals within the next three months.
The federal Department of Veterans Affairs, which contributed $1.2 million to the development of the goggles, will later expand testing to special vision centers in cities around the country, including Chicago, New York and Kansas City.
Barbara Plantholt, president of Triad Investors Corp., Hopkins' for-profit investment corporation, said Triad hopes to begin selling the goggles within the next three years, for about $3,000 a pair.
Researchers, who have worked on the prototype goggles for four years, noted that the device can help only those people who have poor vision, worse than about 20/100, not the blind. The goggles merely project video images in front of the eyes. They are not wired into the brain or the optic nerve.
The goggles, which resemble a huge pair of wraparound sunglasses, are equipped with a single television camera the size of the cap on a felt-tipped marker. The camera sends an electronic signal to a belt pack that contains a battery and electronic signal processor.
The camera's image is then transmitted to a pair of tiny cathode ray tubes on each side of the goggles. A cathode ray tube is the device that projects the video images in an ordinary television.
The image is sent through a prescription lens and bounced by X XTC series of mirrors to the front of the eyes. For the wearer, twin screens merge into a single square window, creating a view roughly equivalent to sitting 4 feet from a television that has a 5-foot screen.
As currently designed, Dr. Massof said, the device could replace the magnifying lenses many people with poor eyesight use to read or work, because the camera can zoom in and out and focus on very small objects as well as landscapes.
Many people have trouble seeing low-contrast details, such as the lips on a face, doctors said. Goggle wearers can turn up the contrast on their eyegear the way television viewers can adjust contrast on their sets, or even reverse the contrast.
The headgear is also lightweight -- the prototype is about 20 ounces. The production model is expected to weigh only 16 ounces. The unit is portable with a rechargeable battery.