The Spectrum of Vision Impairment
When discussing accessibility and sight it can be easy to focus on blindness as the main consideration. However, there is a spectrum of vision impairments to consider when designing course materials.
Image by Lynnthe (Own work) [Public domain], via Wikimedia Commons
There are numerous types of colorblindness, the most common being red/green. However, some individuals have what is referred to as “monochromacy” meaning they see everything in grayscale with no color. When color is used to apply meaning to text or images, it can be a challenge for individuals with color blindness to differentiate these items, and therefore, the overall message may not be visually accessible.
Simulation of Glaucoma by National Eye Institute, National Institutes of Health [Public domain], via Wikimedia Commons
Low vision refers to any eye disease where, even with glasses or contacts, vision is still impaired. Glaucoma is one example, but there are many different forms of low vision impairments.
Individuals experiencing low vision may use a screen reader, or adjust the size of the window on their browser to enlarge the text so that it is easier to read.
Severe or full loss of vision
An individual with severe or full loss of vision must rely on technology to access information on a computer screen in an audible format. Screen readers will provide an audible voice that reads what is on the screen. For basic text this is straight-forward; however, most documents, presentations, and websites also include items like images, headers, links, and other graphics that the screen reader also must decipher. This is where designing courses with screen readers in mind can get tricky. However, the steps that you take to make your courses accessible to screen readers often help most students in many ways that you may not anticipate because they help you keep your documents clear and organized with items properly identified and labeled throughout.
Strategies for Course Design
Hopefully the above information serves as a good introduction of the visual impairments spectrum. You can use some simple tips below to make your courses more accessible to students with these or other visual impairments:
- Use high-contrast: Design pages in your course to be high-contrast. Colors that are similar may be difficult to distinguish.
- Tools like the Colour Contrast Analyser can help assess contrast.
- Avoid using colors to convey meaning (for example in graphs and charts)
- When colors do convey meaning then also include text that clarifies what the colors show. (e.g. "the red line in the graph starts below the green line at X = 0 and then crosses above it at X = 50")
- Keep descriptive text separate from the images. Text that you create inside an image cannot be easily enlarged. For example, a small graphical image that says "Course Syllabus" may be blurry when enlarged. Instead use an icon image of a document and then enter the text "Course Syllabus" manually.
- Avoid animated text that flashes or moves in presentations. Sometimes these animations can be fun, however, be thoughtful in your use.
- Use what is called an “alt tag” or “alt text” whenever you add an image into your course. For example, if you add an image of a child playing with a puppy, in the “alt tag” space you can type “child playing with puppy” and this is what the screen reader will “read” when the user comes to the image.
- Use the default templates in Microsoft Office software including the formatting functions such as available header settings. You can learn more about creating accessible documents and presentations by visiting the following pages in the knowledge base:
Support for Students with Visual Impairments
Depending on the severity of the impairment, the student's experience may range from an annoying inconvenience to a serious daily challenge. Colleges must provide the necessary resources to accommodate students with visual impairment, and instructors can contact their college's office that serves students with disabilities to learn more about resources available and for specific inquiries.
Please contact your school's disability support office for more information about services available for students with visual impairment.