Tennessee v. Lane, 541 U.S. 509 (2004), was a case in the Supreme Court of the United States involving Congress's enforcement powers under section 5 of the Fourteenth Amendment. George Lane was unable to walk after a 1997 car accident in which he was accused of driving on the wrong side of the road. A woman was killed in the crash, and Lane faced misdemeanor charges of reckless driving. The suit was brought about because he was denied access to appear in criminal court because the courthouse had no elevator, even though the court was willing to carry him up the stairs and then willing to move the hearing to the first floor. He refused, citing he wanted to be treated as any other citizen, and was subsequently charged with failure to appear, after appearing at a previous hearing where he dragged himself up the stairs. The court ruled that Congress did have enough evidence that the disabled were being denied those fundamental rights that are protected by the Due Process clause of the Fourteenth Amendment and had the enforcement powers under section 5 of the Fourteenth Amendment. It further ruled that "reasonable accommodations" mandated by the ADA were not unduly burdensome and disproportionate to the harm.
Web designers often design in such a way that does not allow the user to adjust font size or color. While they may be protecting their brand, they are also inhibiting some users. Many visually impaired need to use high contrast color settings or very large fonts to read a website. Don't design your website in a way that makes it impossible for them to do this.
The ADA statute identifies who is a person with a disability, who has obligations under the ADA, general non-discrimination requirements and other basic obligations. It delegates fleshing out those obligations to federal agencies. The agencies issue regulations and design standards. The regulations have the details on the rights of people with disabilities and responsibilities of employers, state and local governments, transportation providers, businesses and non-profit organizations. The design standards specify how many entrances need to be accessible, how many toilet rooms and the design for those elements. To know what the ADA requires, you need to read the law, regulations and design standards.
ADA disabilities include both mental and physical medical conditions. A condition does not need to be severe or permanent to be a disability. Equal Employment Opportunity Commission regulations provide a list of conditions that should easily be concluded to be disabilities: deafness, blindness, an intellectual disability (formerly termed mental retardation), partially or completely missing limbs or mobility impairments requiring the use of a wheelchair, autism, cancer, cerebral palsy, diabetes, epilepsy, Human Immunodeficiency Virus (HIV) infection, multiple sclerosis, muscular dystrophy, major depressive disorder, bipolar disorder, post-traumatic stress disorder, obsessive compulsive disorder, and schizophrenia. Other mental or physical health conditions also may be disabilities, depending on what the individual's symptoms would be in the absence of "mitigating measures" (medication, therapy, assistive devices, or other means of restoring function), during an "active episode" of the condition (if the condition is episodic).