Webpage designers often have aesthetic preferences and may want everyone to see their webpages in exactly the same color, size and layout. But because of their disability, many people with low vision do not see webpages the same as other people. Some see only small portions of a computer display at one time. Others cannot see text or images that are too small. Still others can only see website content if it appears in specific colors. For these reasons, many people with low vision use specific color and font settings when they access the Internet – settings that are often very different from those most people use. For example, many people with low vision need to use high contrast settings, such as bold white or yellow letters on a black background. Others need just the opposite – bold black text on a white or yellow background. And, many must use softer, more subtle color combinations.
Predictable: Websites should operate in ways that are familiar and predictable. When a new page element is in focus, the website should not initiate a change of context such as opening a new window or going to a new page. In addition, the website should warn of user-initiated changes of context ahead of time, for instance through the use of a submit button. Navigation and labeling should remain consistent between different pages.
Videos need to incorporate features that make them accessible to everyone. Provide audio descriptions of images (including changes in setting, gestures, and other details) to make videos accessible to people who are blind or have low vision. Provide text captions synchronized with the video images to make videos and audio tracks accessible to people who are deaf or hard of hearing.
This particular lawsuit amounted to nothing more than a shakedown for cash, as the current laws would make it difficult to win the suit in court (more about this later) but it prompted me to dive deeper into the issue of ADA compliance. Through my research, I discovered there are some new laws on the horizon that could make ADA compliance mandatory, which means web designers and digital marketers need to know how to prepare.
If you have a disability, you must also be qualified to perform the essential functions or duties of a job, with or without reasonable accommodation, in order to be protected from job discrimination by the ADA. This means two things. First, you must satisfy the employer's requirements for the job, such as education, employment experience, skills or licenses. Second, you must be able to perform the essential functions of the job with or without reasonable accommodation. Essential functions are the fundamental job duties that you must be able to perform on your own or with the help of a reasonable accommodation. An employer cannot refuse to hire you because your disability prevents you from performing duties that are not essential to the job.
The Americans with Disabilities Act (ADA) prohibits discrimination against people with disabilities in several areas, including employment, transportation, public accommodations, communications and access to state and local government’ programs and services. As it relates to employment, Title I of the ADA protects the rights of both employees and job seekers. The ADA also establishes requirements for telecommunications relay services. Title IV, which is regulated by the Federal Communications Commission (FCC), also requires closed captioning of federally funded public service announcements.
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.  
The final title contains a variety of provisions relating to the ADA as a whole, including its relationship to other laws, state immunity, its impact on insurance providers and benefits, prohibition against retaliation and coercion, illegal use of drugs, and attorney’s fees.  This title also provides a list of certain conditions that are not to be considered as disabilities.
Aloha Tatiana! I wish your questions had straightforward easy answers – and if you are government funded it kind of is. (See here: https://www.ada.gov/websites2_prnt.pdf) if you are not government funded, this is something that is currently being debated in the legal system. That being said, the WCAG 2.0 guidelines are a good set of guidelines to help protect yourself if you feel you should. (You can see more on WCAG here: https://www.yokoco.com/find-out-how-to-make-your-website-compliant/)