The modern regulatory state draws much of its justification from the notion that profit-driven businesses, unlike public-spirited bureaucrats, will often be tempted to cut corners on safety. But in three cases that the U.S. Supreme Court recently agreed to hear, the stereotypical roles are reversed: Private companies are trying to be extra careful, while the government is encouraging laxer standards.

The explanation for this anomaly can be found in the Americans with Disabilities Act, a 1990 law that forbids employment discrimination "against a qualified individual with a disability." The ADA defines "disability" as "a physical or mental impairment that substantially limits one or more of the major life activities of the individual."

In theory, the ADA does not require employers to hire or retain anyone whose disability makes him unable to perform the "essential functions" of the job, though employers may have to offer "reasonable accommodation," such as wheelchair ramps or electronic readers. To be deemed "qualified," an applicant is supposed to meet "the requisite skill, experience, education and other job-related requirements" for the position.

In practice, the ADA requires courts to substitute their judgment for the employer’s in deciding which functions are "essential," which accommodations are "reasonable," and which requirements are genuinely "job-related." The three cases the Supreme Court is scheduled to hear this spring involve the third question.

In 1992, United Air Lines declined to hire Karen Sutton and Kimberly Hinton as pilots because they failed to meet its 20/100 minimum standard for uncorrected vision. Sutton and Hinton, twin sisters who now fly planes for regional commuter airlines, claim they are "disabled" under the ADA because their uncorrected vision is very poor. But since their corrected vision is 20/20, they say, this disability should not stop them from being pilots for a major airline.

The U.S. Court of Appeals for the 10th Circuit noted the contradiction in this argument: "Plaintiffs cannot have it both ways. They are either disabled because their uncorrected vision substantially restricts their major life activity of seeing and, thus, they are not qualified individuals for a pilot position with United, or they are qualified for the position because their vision is correctable and does not substantially limit their major life activity of seeing."

The Equal Employment Opportunity Commission is urging the Supreme Court to ignore reality and assess the plaintiffs’ disability claim as if eyeglasses and contact lenses--"mitigating measures," in EEOC lingo--did not exist. If Sutton and Hinton are deemed disabled and therefore protected by the ADA, United may be forced to lower its standards for pilots.

While United’s vision requirement goes beyond the criteria for pilots established by the Federal Aviation Administration, the Albertson’s supermarket chain was sued for insisting that its drivers meet the vision standards set by the U.S. Department of Transportation. Hallie Kirkingburg, a truck driver who is nearly blind in one eye, argues that Albertson’s violated the ADA when it discharged him in 1992 because of his disability.

The U.S. Court of Appeals for the 9th Circuit agreed that Kirkingburg is disabled but questioned the relevance of his visual impairment in determining whether he is qualified to be a truck driver. The court noted that Kirkingburg, because of his "impeccable" driving record, had qualified for an experimental waiver program established by the Federal Highway Administration as part of an effort to revise DOT standards in accordance with the ADA.

The United Parcel Service was also complying with DOT regulations when it fired mechanic Vaughn Murphy in 1994 because of his high blood pressure. (UPS mechanics need commercial licenses because they drive trucks as part of their job.) Murphy sued UPS under the ADA, arguing that he is both disabled and qualified.

The 10th Circuit concluded that Murphy is not disabled because his high blood pressure is controlled by medication. As in the United case, the EEOC is asking the Supreme Court to reject that interpretation.

In all of these cases, there is evidence that the plaintiffs could do the job adequately even though they did not meet all the standards. Perhaps it is unreasonable to worry about how well a pilot can see without her glasses, to demand that a truck driver have binocular vision, or to fire a mechanic because his blood pressure is too high.

But all of these rules were designed with safety in mind. If they are revised to maximize job opportunities for the "disabled," there may be a cost to pay.