Reduced vision: contrast, text and icons in a safety app

Size and spacing matter more than tap counts

“I’m OK” and “I need help” ask for a prepared outcome. Chat allows explanation, but requires a recipient, words, keyboard and interpretation. To compare this step with a related case, see One decision per screen: progressive disclosure.

The choice remains the person’s report: it does not measure health, describe the help needed or prove that someone will act.

Contrast, text, icons and an uncluttered screen need testing

W3C treats target size, contrast and understandable content as separate concerns. A button may be large but vague, low contrast or unexpectedly placed.

Try text enlargement, contrast, icons, lighting and an uncluttered screen on the real device. Refer to phone settings without duplicating their instructions. Do not diagnose or infer needs from age.

Two labels work only with an agreement

Agree that “I’m OK” describes the person’s reported state then and “I need help” starts the agreed follow-up. Do not make either also mean “I read it” or “I’m on my way”.

In My Safe Circle, “How are you?” request replies are separate outcomes; message and location remain optional.

Buttons and chat compared

The matrix describes trade-offs, not a universal ranking.

When chat or a call is needed

Use chat when context, questions, an address or instructions are part of the task and the person can communicate. One button cannot say what help to bring. The same operational plan is developed further in Delivered, read, understood, acknowledged: four different things.

Call directly for immediate danger, when voice is clearer or when a fact needs confirmation. Do not wait for an app reply.

Test understanding and follow-up

Run an announced rehearsal: ask the person to choose and explain what will happen. Check recipients, alerts, network, confirmation and backup; do not claim universal speed.

Concrete example: With recognition, the option is present: someone sees “SOS”, “ALL OK” or “I need help” and compares it with their intent. Recall means remembering that a particular icon, long press, sequence or menu item produces an effect. The recognition-over-recall heuristic encourages visible objects, actions and choices. Contrast, text, and icons help only when this person can perceive and understand them; no combination is universal, so respect preferences, test assistive use, and keep voice or calling as an alternative.

Useful counterexample: This is design guidance, not a law that recognition is always easy. A word may be unfamiliar, a label too small, a translation unnatural or two choices too similar. Familiarity, vision, attention, literacy, language, assistive technology and context affect the result. Contrast, text, and icons help only when this person can perceive and understand them; no combination is universal, so respect preferences, test assistive use, and keep voice or calling as an alternative.

Concrete example: For “Reduced vision: contrast, text and icons in a safety app”, With recognition, the option is present: someone sees “SOS”, “ALL OK” or “I need help” and compares it with their intent. Recall means remembering that a particular icon, long press, sequence or menu item produces an effect. The recognition-over-recall heuristic encourages visible objects, actions and choices. Keep the choice proportionate to purpose and the person’s preferences; if this route does not fit, use the second channel or appropriate local service without inferring delivery, understanding, or intervention.

Relevant counterexample: For “Reduced vision: contrast, text and icons in a safety app”, This is design guidance, not a law that recognition is always easy. A word may be unfamiliar, a label too small, a translation unnatural or two choices too similar. Familiarity, vision, attention, literacy, language, assistive technology and context affect the result. Keep the choice proportionate to purpose and the person’s preferences; if this route does not fit, use the second channel or appropriate local service without inferring delivery, understanding, or intervention. Before testing, check the features described on the website.

• Do the labels have agreed meanings?
• Can the person read and distinguish them?
• Does the recipient know the action?
• Are message and location optional?
• Are call, SMS and backup ready?

A choice does not prove an emergency or guarantee action. With concrete immediate danger call local services; 112 is common and free in the EU.

Frequently asked questions