The Centers for Disease Control and Prevention (CDC) define “vision impairment” to mean that a person’s eyesight cannot be corrected to a “normal level.” Vision impairment can result from a variety of conditions, injuries, or eye diseases. There are varying degrees of vision impairments ranging from mild vision loss, such as slightly hazy or blurry vision, to total blindness.
Whether you use images or charts to help explain concepts in your online course; require students to reflect on or discuss an image posted by you or their peers; or use images in your tests, describing them in detail can greatly help students with visual impairments the same way video captioning does for the hearing impaired.
WebAIM—a non-profit organization that provides web accessibility solutions—lists appropriate alternative text as the first principle of web accessibility. Alternative text, as the name implies, provides textual alternative to non-text content. Description of an image is a form of alternative text and can be presented in two ways: within the context or surroundings of the image itself; or within the alt attribute of the img tag.
What to Describe
Take a closer look at one of your images, then ask yourself the following questions: What does the image convey? What is most essential? What is happening? Who is/are in the image?
The first rule of description, according to Audio Description Guidelines and Best Practices by The American Council for the Blind, is to describe what you see or W.Y.S.I.W.Y.S. (What You See Is What You Say.) Generally, describe what is most essential for students to know in order to follow or understand the intended learning outcomes. Describe shape, size, texture, or color as appropriate to the comprehension of the content. Describe individuals by using the most significant physical characteristics. If unable to identify people by name, identify ethnicity/race as it is known and vital to the comprehension of the content. Provide as much details using as few words as possible. Too much description can be distracting or even irritating.
How to Describe
Writing quality description of an image is a thoughtful and time consuming process. In “A Picture is Worth 300 Words: Writing Visual Descriptions for an Art Museum Web Site,” Adam Alonzo provided some guidelines for visual descriptions.
- Be objective: Stick to the facts, avoid analytical interpretations or emotional responses.
- Be brief: Shorter is better, avoid redundant phrases.
- Be descriptive: Use words that convey clear and vivid meaning. Include color, shape, size, and texture of an object.
- Be logical: Use a sequence or structure such as left to right or top to bottom. Place adjectives after the word they modify. For example, use “her hair is long and wavy” instead of “long, wavy hair.”
- Be accurate: Make sure information you give matches other credible sources.
Context is Everything
The description of one image may be significantly different based on the context or surroundings of the image. Two key factors when writing appropriate description is to determine 1) the purpose of the image (informational or decorative/entertainment) and 2) the information being presented in the image.
A. Kofi Annan
B. Nelson Mandela
C. Desmond Tutu
D. Kwame Nkrumah
In this example students are asked to identify the man in the photo. The image conveys information but the description cannot give away the answer.
A South African freedom fighter who became the first elected president in a fully democratic election looks to be in his eighties. He has dark complexion and very short, white hair. He is smiling and wears a gold shirt.
Nelson Mandela was a South African anti-apartheid revolutionary, politician, and philanthropist who served as President of South Africa from 1994 to 1999. He was South Africa’s first black chief executive, and the first elected in a fully representative democratic election. His government focused on dismantling the legacy of apartheid through tackling institutionalized racism, poverty and inequality, and fostering racial reconciliation. Politically an African nationalist and democratic socialist, he served as President of the African National Congress (ANC) from 1991 to 1997. Internationally, Mandela was Secretary General of the Non-Aligned Movement from 1998 to 1999.
(Photo: South Africa The Good News [CC BY-2.0] via Wikimedia Commons
In this example the image conveys information that is presented in the surroundings of the image.
“Nelson Mandela” is likely the most appropriate description in this context.
Proper hands and arms positioning are important in performing chest compression. See the example below for a demonstration of correct position.
Place the heel of one hand over the center of the person’s chest, between the nipples. Place your other hand on top of the first hand. Keep your elbows straight and position your shoulders directly above your hands.
Place the heel of one hand over the center of the person’s chest, between the nipples. Place your other hand on top of the first hand. Keep your elbows straight and position your shoulders directly above your hands. See example for proper hands and arms positioning.
Use your upper body weight (not just your arms) as you push straight down on (compress) the chest at least 2 inches (approximately 5 centimeters).
(Illustration: How to Do CPR on an Adult on WikiHow [CC BY-NC-SA 2.5] Text: Cardiopulmonary resuscitation (CPR): First aid on Mayo Clinic)
Like example 1B, the image in this example conveys information that is already presented in the surroundings of the image.
An empty alt attribute “ ” or “hands and arms positioning” would be appropriate description.
No Single Right Way
There are many ways to describe images. The best description will depend on the context and the intended information or learning outcomes. Ask yourself: Is this something the students really need to hear?
If you are interested in learning more about image description for people with vision impairments, visit:
Alternative Text and Accessible Images on WebAIM website
A Picture is Worth 300 Words: Writing Visual Descriptions for an Art Museum Web Site
This article is inspired by an Accessing Higher Ground conference session: Strategies for Representing Graphics: from eText to Alt Tags to Tactile.