The term for the visually impaired is legal blindness. What constitutes legal blindness depends on who you speak to.
For starters, the legally blind have greater than 0% vision (not comparable to total blindness), whereas any visual acuity of 20/200 or worse in their better eye can be classified as that. At the same time, if your visual field is less than 20° (tunnel vision), you can also be considered legally blind. Diminished visual acuity may require the use of glasses or contact lenses.
Keep reading to learn more about what it means to be legally blind, how visual acuity and field division work, and how legally blind prescriptions are measured. Also, website accessibility widgets like Accessibly can help improve the navigational experience on websites and mobile applications for this group.
Legal Blindness
Legal blindness/limited visual acuity includes but is not limited to, cataracts, age-related macular degeneration, and diabetic retinopathy, which represents diabetes-related damage to retina blood cells. Others, like age-related macular degeneration, encompass a loss of central vision. In contrast, other lesser-known conditions like retinitis pigmentosa are a group of genetic disorders that attack the retina over time.
Solutions by Accessibly
Accessibility overlay widgets like Accessibly offer several features for the visually impaired to navigate websites. These features include customizable color contrast, text-to-speech, the best fonts and sizes, larger cursors, and other enhancements that completely transform how users interact with web pages. Additionally, Accessibly provides keyboard navigation aids, allowing for the effective use of shortcut keys to interact with elements instead of relying on mouse movement.
Enjoy a free 7-day trial for instant access to all of Accessibly’s features. Follow ADA and WCAG compliance with this lightweight widget that takes no more than 5 minutes to install. It consists of a snippet of code that can be hard-coded onto any website.
Introduction to Legal Blindness: Definition and Criteria
Over the past few years, new criteria have been established for determining legal blindness. According to the American Foundation for the Blind, the Social Security Administration, and the World Health Organization, if you have visual acuity of 20/200 or worse in your better eye, or if your visual field measures less than 20 degrees, you may be diagnosed with tunnel vision. By helping establish clear criteria, these guidelines enable individuals with this type of visual impairment to determine their eligibility for disability benefits and access support and resources aimed at improving the quality of life for those with low vision and the legally blind.
Legally Blind Prescriptions: A Word on Legally Blind Prescriptions
One of the best ways to understand legal blindness is by examining prescription guidelines. Prescriptions refer to the corrective lenses needed for individuals with 20/200 vision or worse. If corrective lenses fail to improve vision beyond this threshold, you are automatically considered legally blind, which can prevent you from performing everyday activities with confidence.
Two factors are used to determine legal blindness: visual acuity and field of vision. Visual acuity is expressed as a ratio, such as 20/200, where the first number represents what a person can see at 20 feet, compared to what an average person can see at 200 feet. In contrast, the field of vision refers to one’s peripheral ability—how much one can see while looking straight ahead without moving the head or eyes. Visual field tests, also known as perimetry tests, measure how far one’s eyes can see both vertically and horizontally without head or eye movement.
The higher the number of degrees, the better the field of vision. Typically, the maximum horizontal field of vision is 180 degrees, while the vertical field can extend to approximately 135 degrees in the stronger eye (with or without glasses). If vision is more restricted than this, it may be classified as tunnel vision or legal blindness.
Sometimes, there are other ways to address legal blindness, such as surgery or other measures, to determine the severity of the condition.
A Word on Bad Peripheral Vision
Peripheral vision allows us to see things outside of our line of sight.
Individuals with poor peripheral vision may have difficulty driving, shopping, or performing everyday tasks. As a result, they may rely on using objects in different quadrants of their field of vision to guide their paths.
According to the Social Security Administration, a visual acuity of 20/200 or worse in the better eye classifies as legal blindness. One popular test used to evaluate visual acuity is the Snellen eye chart, which allows people to test their eyesight at various distances. Anyone can use this chart to test their vision, including a legally blind person or someone with low visual acuity.
Key Tools and Technologies
For the visually impaired, three of the most critical accessibility tools are screen readers and magnification software for mobile and web applications. Despite having similar names, screen readers and magnification software serve different purposes.
Screen Readers
Screen readers help those with low vision convert digital text to synthesized speech or Braille, allowing for effective text-to-speech conversion, keyboard navigation, and even Braille support, where users can work with refreshable Braille displays and receive tactile feedback. This assistive technology can read the text displayed on a computer screen aloud in a neutral accent, allowing the visually impaired to hear audible messages about what appears on screen, such as form buttons and error messages.
Three of the more popular screen readers are JAWS (Job Access With Speech), NVDA (NonVisual Desktop Access), and VoiceOver by Apple. All offer excellent text-to-speech capabilities, including the ability for users to control their devices using hand gestures, Apple’s Siri, and keyboard commands. TalkBack for Android allows users to control their devices using gestures.
Magnification Software
Programs like ZoomText or Windows Magnifier allow those with low vision to amplify any element on a screen, making them easier to tell apart. They also offer built-in high contrast settings and improve text and background color ratios, making readability better.
Braille Displays
Braille displays are also used by those with low vision, which help transform on-screen text into Braille. They can be used on virtually any device, from computers to tablets, working dynamically and in real-time using small raised pins that can be felt to interpret any item on a web page, including document text.
Additionally, many accessibility tools like JAWS (Job Access With Speech) further enhance Braille display functionality. For example, BrailleNote can be used for quick email access, whereas JAWS converts content into Braille in real time. Users can also navigate entire documents and web pages using a series of shortcut commands, improving overall workflow.
Screen readers, magnification software, and Braille displays significantly promote accessibility and increase the quality of life for those with low vision, poor eyesight, tunnel vision, those wearing corrective lenses, and more.
Accessibly’s Solutions for the Legally Blind
If you or someone you know is legally blind, one of the best ways to improve the online browsing experience is by using web accessibility overlay widgets like Accessibly. Accessibly is a lightweight application that helps businesses comply with the Web Content Accessibility Guidelines (WCAG). These internationally recognized guidelines inform how physical and digital workspaces are built for individuals with disabilities, including accessibility for the visually impaired
Features available through the Accessibly app include, but are not limited to, text magnification, color contrast adjustment, text spacing control, screen reader compatibility, and more. It also enhances keyboard accessibility; many website elements (e.g., form fields) can’t be fully navigated using only a series of keyboard shortcuts, providing an alternative to moving your mouse.All new Accessibly Accessibility Widget users (including those with low vision) can enjoy a free 7-day trial. Feel free to test drive all features before committing to a subscription starting at $20 per month. Follow the ADA and WCAG guidelines and download the Accessibly ADA accessibility overlay widget now!
