WASHINGTON – The government discriminates against blind people by printing money that all looks and feels the same, a federal judge said Tuesday in a ruling that could change the face of American currency.

U.S. District Judge James Robertson ordered the Treasury Department to come up with ways for the blind to tell bills apart. He said he wouldn’t tell officials how to fix the problem, but he ordered them to begin working on it.

The American Council of the Blind has proposed several options, including printing bills of differing sizes, adding embossed dots or foil to the paper or using raised ink.

“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. “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.”

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.

He said the government was violating the Rehabilitation Act, which prohibits discrimination on the basis of disability in government programs. The opinion came after a four-year legal fight.

Electronic devices are available to help blind people differentiate between bills, but many complain that they are slow, expensive and unreliable. Visually impaired shoppers frequently rely on store clerks to help them.

“It’s just frankly unfair that blind people should have to rely on the good faith of people they have never met in knowing whether they’ve been given the correct change,” said Jeffrey A. Lovitky, attorney for the plaintiffs in the lawsuit.

Others have developed ways to cope with the similarly shaped bills. Melanie Brunson, a member of the American Council of the Blind, told the court that she folds her bills into different shapes: $1 bills stay straight, $5 bills are folded in half left to right, $10 bills in half top to bottom and $20 in quarters.

The Treasury Department had no comment on the ruling Tuesday. The government has 10 days to decide whether to appeal.

In court documents, government attorneys said changing the way money feels would be expensive. Cost estimates ranged from $75 million in equipment upgrades and $9 million annual expenses for punching holes in bills to $178 million in one-time charges and $50 million annual expenses for printing bills of varying sizes.

Any change to the dollar’s design could ripple into the vending machine industry, which participated in discussions regarding previous redesigns.

The American Council of the Blind is not seeking changes to the $1 bill, according to court documents.

The Treasury Department spent $4.2 billion on printing over the past decade, Robertson said. Adding a raised number to the bills would have increased costs less than 5 percent over that period, he said.

“If additional savings could be gained by incorporating the new feature into a larger redesign, such as those that took place in 1996 or 2004, the total burden of adding such a feature would be even smaller,” Robertson wrote.