American paper money represents an unfair impediment to the blind, and the Treasury Department must come up with new U.S. currency to help the visually impaired use cash, a federal judge ruled Tuesday.

U.S. District Judge James Robertson said keeping all U.S. currency the same size and texture violates the Rehabilitation Act, which prohibits discrimination on the basis of disability in government programs.

"Of the more than 180 countries that issue paper currency, only the United States prints bills that are identical in size and color in all their denominations," Robertson wrote in his ruling. "More than 100 of the other issuers vary their bills in size according to denomination, and every other issuer includes at least some features that help the visually impaired."

Day Al-Mohamed, director of advocacy and government affairs at the American Council of the Blind, said that most of the world's currency is distinguished by color, size, perforations or tactile symbols. The Euro, for instance, can be determined by the length of the bill — the higher the denomination the longer the bill.

"Saudi Arabia has money that varies in size based on denomination," she said. "If so many other countries can do it, why not the greatest country in the world?"

"It's exciting from our perspective. It's an area that doesn't get a lot of attention. I give ACB a lot of credit for hanging in there," said Andrew Imperato, president and CEO of the American Association of People with Disabilities. "Hopefully it's just going to make blind people able to live more independently."

But John Paré, director of public relations for the National Federation of the Blind, the nation's largest organization representing blind people, said identifying the money is hardly the most difficult obstacle for the blind to overcome.

"The focus for improving the lives of blind Americans needs to be put on earning money not figuring out how to identify money," he said. "Over 70 percent of blind Americans are under-employed or unemployed and this is what needs to be addressed.

"It really is distracting to have this lawsuit," he said, since assistance should concentrate on people "who don't have the money in the first place."

Blindness is measured as 20/2,200 or worse vision, according to Al-Mohamed, who said many more people with still limited sight have better vision than that.

About 7 million Americans are blind or visually impaired, and the numbers are expected to increase by 4 million by 2015 as baby boomers age, Al-Mohamed said. The majority of people with vision loss problems get them after age 45, she said.

For many blind, working with currency often relies on the "kindness of strangers," Al-Mohamed said.

Paré and Al-Mohamed agree that current tricks help the blind manage their cash, for instance folding different size denominations different ways and leaving one dollar bills crumpled.

"There are techniques for identifying currency that blind people utilize today that work reasonably well," Pare said. "Every single organization that deals with teaching blind people how to deal with currency teaches how to do that."

But Al-Mohamed said that blind people often resort to using note-tellers, portable readers that can cost $300 per machine. Often, they don't work when bills have been folded or crumpled and frequently it's inconvenient to use in a busy store, she said.

"The way a lot of people distinguish bills now is they rely on a cashier to tell them what bills are and fold them different ways, but that's kind of a vulnerable situation," Imparato added.

In the lawsuit, which has been in the court system for four years, government attorneys argued that forcing the Treasury Department to change the size of the bills or add texture would make it harder to prevent counterfeiting. Robertson was not swayed.

"The fact that each of these features is currently used in other currencies suggests that, at least on the face of things, such accommodations are reasonable," he wrote.

"I'm sure there were concerns around the cost of coming out with all these new bills (to prevent counterfeiting)," Imparato said. "When you're already going through the cost of the new design, I don't think it would cost a lot more to build in accessibility."

He acknowledged that many Americans may not want to make the change to different sized currency. Several attempts to move U.S. currency to a dollar coin have failed in the past, though the Treasury Department announced last week that it is going to give it another go with new coins struck with images of the deceased presidents.

"The main argument in favor of not doing that is tradition, and tradition and accessibility do not always mix," Imparato said.

Robertson wouldn't say how Treasury must do it, but he gave the government agency 10 days to start working on new bills that the blind can tell apart.

The Treasury Department refused to comment on the case, saying that it's still pending. Paré said that his organization wasn't involved in the lawsuit, and he can't speak for the Treasury Department, but he did "get the sense that it was going to be appealed."

Al-Mohamed said she expects members of her organization will have a sit-down soon with Treasury officials to consider changes to be made. She said the group is not overly particular about which changes are offered as long as they are helpful and can be done in a reasonable amount of time. She said already several of the Bureau of Engraving and Printing's presses are set up to deal with specific denominations.

"I don't think it quite matters as long as it allows for identification without sight," she said of any proposed changes. "Sooner is better" but it "depends on the changes being used."

ACB is not going to demand of Treasury "wild and crazy changes, you have to do it now," she said.

FOXNews.com's Sharon Kehnemui Liss and Catherine Donaldson-Evans and The Associated Press contributed to this report.