he vans pulled up at the Leben Home for Adults in Elmhurst, Queens, collecting the mentally ill residents who had been led outside and told to take a seat. Among them were Robert Dowling, who communicates in half-sentences and twitches; his roommate, Robert Fazio, who cannot bathe or dress himself; Seymour Levine, stooped and unkempt; and Gail Barnabas, so depressed she sometimes does not speak.

None of them resisted, as if they were being chaperoned to a movie or a ballgame. The doors closed and the vans headed for the offices of a doctor who billing records show had never examined some of the residents, but who was about to perform a variety of eye surgery on them.

The scene would be repeated throughout 1999 and 2000, a few residents at a time. In all, the doctor conducted nearly 50 operations on more than 30 residents, the billing records show.

"So many people were having the eye surgery, it was like it was a catchable disease," recalled Peter Peterson, one of the more alert Leben residents.

Few of the residents had been complaining about their eyesight, and their general physicians had not noted problems with it, according to Leben workers and medical records. Neither the ophthalmologist, who had built a substantial practice around adult home residents, nor Leben notified their families.

The procedures, which ranged from cataract operations to laser surgery and required local anesthesia, cost the government more than $25,000, the billing records show. To this day, most of the residents cannot explain what was done to them, or why. Then again, having spent much of their lives in institutions, most are used to not asking questions.

The State Department of Health, which regulates adult homes, did not learn of the eye operations until they were uncovered by The New York Times. The department is now investigating them.

Ever since New York began closing its psychiatric wards in the 1960's and essentially replacing them with adult homes, the for-profit residences have become magnets for schemes that exploit the mentally ill, a yearlong investigation by The Times found. The investigation drew upon thousands of pages of billing and medical records and state files, as well as more than 200 interviews with workers, residents and family members.

Those interviews and records show that at several homes, what little money some residents have is simply stolen by the operators. At dozens of homes, residents are brought before a swarm of outside providers for treatment — from surgery to allergy shots — that seems more intended to generate revenue from government programs than to improve residents' well-being.

The State Department of Health, in fact, knew well before the eye operations that doctors might be taking advantage of residents at Leben, long one of the state's most notorious adult homes. In early 1998, department officials began investigating a complaint, later substantiated, that two doctors had coerced 24 Leben residents into having unnecessary prostate surgery.

Yet the department's records show it otherwise ignored the home, and did not increase oversight or take precautions to safeguard the people who lived there — or at any other adult home, for that matter. In the regulators' absence, at least eight Leben residents who had had the prostate surgery then had the eye procedures, according to billing records and interviews.

The Health Department would not comment on its investigation of the eye operations. The ophthalmologist, Dr. Shaul Debbi, would not comment, citing the privacy of his patients. Leben's operator at the time, Jacob Rubin, would also not comment. He was removed by the state in May 2001 after The Times published two articles about malfeasance at the 361-bed home.

As with so much else involving adult homes for the mentally ill, this was not the way it was supposed to be. The homes, conceived as a decent alternative to the dead-end misery of the state psychiatric hospitals, were intended to give the mentally ill a chance at lives in which they might have jobs, receive better care and join society in an authentic way.

Instead, The Times's investigation shows, many of the homes have become another universe in which the mentally ill are taken advantage of and poorly served.

On one side are the homes' operators, a group of businessmen who include a disgraced lawyer and a state senator's husband who went unpunished by state officials despite stealing money from residents, court records show. On the other side are the providers, which include hospitals and doctors with tarnished state records. One nonprofit group, which offers psychiatric therapy to residents, even took the opportunity to use more than $1 million in government payments to engage in risky stock trading, according to its tax records.

In the middle are thousands of vulnerable people. Nearly all the residents can legally sign consent forms, and persuading them to do so is not hard. Workers at several homes said that if residents do refuse to see doctors or other providers who have financial arrangements with the operators, administrators threaten to hospitalize the residents or to withhold their spending money, which is typically entrusted to the homes.

"We would usually tell them, `You don't see the doctor, you don't get your allowance,"' said Velma McFarlane, a former Leben worker. "I had to do that. I'm not lying. It makes me feel bad, but that was the policy."

Some residents undoubtedly require an array of services. Studies have shown that mentally ill people suffer higher rates of heart disease, diabetes and other ailments. Some may also be resistant to care that they genuinely need.

Yet at virtually all the 26 homes The Times examined, workers and residents spoke of coercive tactics aimed at dubious needs. While residents often go without proper psychiatric or medical care, they are paraded before allergists, vocational therapists, dermatologists and podiatrists, among others.

The government should not be shocked that the system is rife with seeming abuse and waste. The way in which the state set up the homes all but invited it.

The state decided it would pay the homes a small daily sum — still only $28 per person — to feed, shelter and supervise the residents. The fee is taken from the residents' monthly Social Security disability checks.