The meaning of “disability” has shifted with changes in public policy. Half a century ago, Congress was convinced that narrow determinations of disability are easy for physicians to make. But with the advent of universal civil rights protection against disability discrimination in the US, deciding whether particular individuals are disabled became increasingly contentious, until Congress intervened. What should now be addressed in each case is not whether the functionally compromised person is severely disabled enough to exercise a right, but whether mitigating interventions and reasonable accommodations can together achieve equitable access for that person.
Francis L., Silvers, A., AMA Journal of Ethics. October 2016, Volume 18, Number 10: 1025-1033. doi: 10.1001/journalofethics.2016.18.10.pfor2-1610.