527 U.S. 471 (1999)
Sutton v. United Air Lines, Inc.
Under the ADA, must courts consider mitigating measures (such as corrective lenses) when determining whether a person is substantially limited in a major life activity, and does an employer's refusal to hire based on a vision standard for one pilot job constitute regarding an individual as substantially limited in the major life activity of working?
Pre-ADAAA ADA: (1) Whether an impairment "substantially limits" a major life activity is determined in light of mitigating measures actually used by the individual; (2) To be "regarded as" disabled, an employer must perceive the person as having an impairment that substantially limits a major life activity; for working, the perceived limitation must preclude a broad class or range of jobs, not merely a single, particular position.
Yes, mitigating measures must be considered in assessing disability under the ADA; and no, regarding an individual as unfit for a single job based on a specific job requirement does not establish that the person is regarded as substantially limited in the major life activity of working.
Sutton narrowed the ADA's coverage by requiring courts to factor in mitigating measures when determining disability and by confining "regarded as" claims to perceptions of broad job-class limitations. The decision led many ADA plaintiffs to fail at the threshold disability inquiry. In 2008, Congress enacted the ADAAA, expressly rejecting Sutton's mitigating-measures rule in most contexts and broadening the "regarded as" prong so that adverse action taken because of an impairment generally suffices without proof of substantial limitation. Notably, however, the ADAAA preserves an exception for ordinary eyeglasses and contact lenses when evaluating visual acuity, so Sutton's bottom-line result for corrected myopia may still hold under the actual-impairment prong. For law students, Sutton is vital for understanding pre- and post-ADAAA frameworks, the analysis of the major life activity of working (including the class-of-jobs concept), and the role of agency guidance in statutory interpretation.