For many, "blindness" is often considered to be the inability to see out of either eye. To the contrary, the definition of blindness isn't so black and white and can come in varying degrees. It includes several different characteristics, including total loss of vision, partial blindness, or limited vision.

The legal definition of blindness is used to determine the individuals eligibility for benefits and participation in programs. The United States defines that a person can be considered legally blind when they have a visual acuity of 20/200 with corrective lenses or who has a field of vision that is 20 degrees in the eye that has the better vision.

Normal vision vs. Blindness

Normal vision vs. Blindness

Visual Acuity

Visual acuity is a measure of the eye's ability to distinguish the smallest identifiable objects, such as a letter or symbol from a given distance. It is the clarity and sharpness of vision. If you have been to they eye doctor, there is a good chance that your visual acuity has been tested. Commonly, the doctor has you stand 20 feet from a chart and read the smallest letter and object that you are capable of. If someone has 20/20 vision, they were able to see clearly at 20 feet. When a person has 20/200 vision, that means that what they are able to see at 20 feet is what a person with 20/20 vision can see at 200 feet.

Field of Vision

A field of vision is the line of sight that a person has without moving their eyes left or right; it is a fixed position.

Total blindness is when there is no visual light perception and there is lack of form.

Causes of Blindness

There are many ways for an individual to become blind. It can be gradual, due to an accident, or from a disease.

Common causes of blindness include:

  • Eye Disease (Macular degeneration or Glaucoma)
  • Diabetic Retinopathy (Type 1 or Type 2 Diabetes)
  • Stroke Related Vision Loss
  • Eye Surgery Complications
  • Congenital Eye Defects

When a person is born or becomes blind they navigate the world in different way, including navigating computers and web pages.

From canes to reading glasses, individuals who are blind rely on various assistive technologies in order to navigate the physical world. In order to navigate the digital world and engage and interact with computers and mobile devices, people who are blind rely on assistive technology called screen readers. On desktop computers, where the primary input is typically a keyboard and mouse or trackpad, the visual requirements that are required in order to operate a mouse must be overcome. Likewise, from a mobile device, where the visual interface requires touch and swipe commands in order to operate the device, an alternative means of access must be provided. Enter the assistive technology known as screen readers.

Screen readers are a software applications that convert text into synthesized speech. They allow users to hear what content is displaying and being interacted with. To navigate, a user avoids the use of the mouse by leveraging keyboards commands or by engaging a braille reader display that provides additional options for those versed in the tactile writing system. On mobile devices, specific tap and swipe commands drive the audible user experience. Likewise, keyboards or braille reader displays may be connected for a more immersive experience. For example, when navigating a website through a web browser on a desktop computer, the screen reader technology will audibly read aloud as the user encounters different elements such as headers, links, and form fields. When the screen reader user encounters a link, for example, they may press enter on the keyboard to follow the link. The user is provided with a multitude of keyboard commands and shortcuts to interact with their computer or device.

As it pertains to navigating the web, the screen reader software's capacity to understand the contents of a website is dependent on the level of accessibility of the website. In other words, the extent to which the web developers adhered to coding best practices, in particular, the internationally recognized standards outlined under the W3C's Web Content Accessibility Guidelines 2.0, will determine how accessible and usable the user experience is for those relying on screen reader technology to engage and interact with the website.

Making websites accessible for users of assistive technologies, such as screen readers, is a primary focus of Web Accessibility and ADA-related compliance. Web Accessibility is rooted in the principles of Universal Design, which offers great benefit for everyone. When builders adhere to these principles, they provide ramps and rails for individuals in wheelchairs, they make available drinking fountains and kiosks of varying heights for those sitting vs. standing. Automatic opening doors, tactile paving, and curb cuts are just a few examples of how Universal Design can provide great benefit to individuals with disabilities... or, even, parents pushing their child in a stroller, or a delivery person transporting goods on a rolling cart, etc.

When applied to making digital environments accessible, these same concepts apply. When a webpage is coded properly, screen readers are able to read menus, text, graphics, buttons, and forms using the keyboard commands. If not coded properly, the web page will contain barriers, making the screen reader unable to verbalize to the user what is on the page. But the benefits, of course, are not limited to a specific use case, such as blindness. Other disabilities are addressed when web designers, content authors, and programmers conform to the principles of Universal Design. When designed, authored, and developed with digital inclusion in mind, websites can be made available in an equitable manner for all users, including individuals with color blindness, low vision, physical or mobility impairments, cognitive disabilities, and those looking to maintain focus or learning to read.

For a website to be accessible for people who are blind, it must be perceivable, operable, understandable, and robust (WCAG 2.0). Learn more about making websites accessible to individuals with disabilities through WCAG 2.0.

AudioEye Developer Tools for Evaluating and Fixing Issues Impacting Users with Blindness

The AudioEye Digital Accessibility Platform provides developers with tools for testing issues of accessibility, many of which impact users of assistive technologies, such as screen readers. The tool can also be used to remediate issues for those customers embedding the AudioEye JavaScript. In addition to helping ensure designers and developers have taken careful measure to design and develop their web environments with techniques that help improve the user experience for blind users, AudioEye also provides a series of assistive tools that are included with the Ally solution offering.

Learn more about the Digital Accessibility Platform

AudioEye Personalization Tools Addressing Issues Impacting Users with Blindness

The AudioEye Ally Toolbar provides users with blindness with several options to optimize the user experience to meet their needs. The Ally Toolbar comes with a screen-reader-like user experience called the Player. This utility allows users to listen to site content read aloud through a sophisticated and automatic text-to-speech process. Users can use basic key commands to listen and navigate website content or engage and interact with web forms and other site elements.

Learn more about the Ally Toolbar

Source Materials:

Living with Vision Loss: Assistive Technology

Kaely Wang

Read more posts by this author.

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