Approximately 20% of the world’s population is living with at least one disability. A majority of times, these disabilities restrict the individual from completely benefiting from the resources of the Internet. Many businesses have a Web page on the Internet that has some type of limitation for someone with a disability. Businesses that do not maintain accessible Web sites are ignoring a vital portion of the population and because business owners rely on Web designers, it is the Web designer’s responsibility to create accessible Web sites. Web designers use a variety of techniques to ensure Web sites are accessible for users with disabilities; including, visual impairments, physical impairments, cognitive impairments, and hearing impairments.
People with normal vision are able to view images, understand visual cues, and understand the symbolic meanings’ of colors and shapes. However, people with vision impairments cannot always understand the images and colors presented to them from a Web page. There are different types of vision impairments that effect users of a Web site in different ways. Web designers need to consider different levels of sight impairments when designing a Web site. People with sight impairments; including, no vision, limited vision, and color blindness have different accessibility needs that should be designed for accordingly.
Accessibility for individuals with vision เว็บตรง impairments include; resizing text, color contrast; including, alt and skip text, and compatibility with screen readers. Color contrast includes using colors that compliment each other and font colors that are easily legible. For example, text background and font color that are too similar are difficult or impossible for people with colorblindness to differentiate. Colors must also have the ability to be changed to black and white or magnified without distorting. Text size is an important factor for people with limited sight. Small font on a Web site can be very difficult to read and should have the ability to be enlarged. Elderly people that require reading glasses would have difficulties reading small text and find using the site cumbersome. When there are images on a Web page, they should be labeled with an alternative information source, known as an alt tag or alt text. Alt text allows assistive technology devices to read a Web site and interpret images appropriately. Skip text triggers assistive technology devices to skip the content. This is used with repetitive, non-critical information like the logo of the site on pages other than the home page and for menus that are found in multiple locations on the same page.
Hearing is another classification of a disability that can affect the way a person receives information from a Web site. The technologies used on the Internet enable people to watch videos, listen to music, and use other types of audio devices. Web designers should implement technology and methods that allow people with hearing disabilities to obtain information using a different mode. Hearing Impairments can be compensated for by using accessibility strategies related to any type of audio on the site; specifically audio that communicates information. For Web pages that contain audio information, a caption alternative should be available for people who need it. If there is video embedded into a Web page, this too should have a caption alternative for people with hearing disabilities. These alt tags can work similarly to those used for individuals with vision impairments as they are not seen by the sighted user but can be accessed by assistive technology. Providing a transcript for Web pages that provide podcasts will help a site be more accessible.