Reasonable accommodation is the key to understanding the ADA.

Examples of reasonable accommodation include making existing facilities used by employees readily accessible to and usable by an individual with a disability; restructuring a job; modifying work schedules; acquiring or modifying equipment; providing qualified readers or interpreters; and appropriately modifying examinations training, or other programs.

Reasonable accommodation also may include reassigning an employee to a vacant position for which the individual is qualified, if the person is unable to do the original job because of a disability even with an accommodation. However, there is no obligation to find a position for an applicant who is not qualified for the position sought. Employers are not required to lower quality or quantity standards as an accommodation, nor are they obligated to provide personal use items such as glasses or hearing aids.

The decision as to the appropriate accommodation must be based on the facts of each case. In selecting the particular type of reasonable accommodation to provide, the principal test is that of effectiveness, i.e., whether the accommodation will provide an opportunity for a person with a disability to achieve the same level of performance and to enjoy benefits equal to those of an average, similarly situated person without a disability.

However, the accommodation does not have to ensure equal results or provide exactly the same benefits. Source: Consumerlawpage.com