DevFest Vienna 2025: How Blind People Navigate the World, On and Offline

Source: Dev.to

Online Navigation

Online navigation works quite similarly to offline navigation, only the tools differ greatly. For online navigation we mainly have zoom, screen magnifiers, and screen readers (SR). Zoom and screen magnifiers are pretty easy to understand – they simply make things big.

Screen readers are more intimidating at first. You boot them up and suddenly everything starts talking! Most of us aren’t fond of unexpected noises, but text‑to‑speech (TTS) is the intended functionality of screen‑reader software. The monotone, technical‑sounding voices can be overwhelming, especially when you have to concentrate on what they’re describing. Braille displays peacefully coexist with TTS screen readers and are a staple for web access.

Screen Reader Output

Screen readers don’t just read what’s visible on the screen; they read what you wrote into your code. A software tester using a mouse might not notice that a menu “exit” button is actually a styled ```, but the SR will, and it may not work as expected.

This is where the accessibility tree comes into play. The accessibility tree is how SRs and other assistive technologies navigate a website, climbing heading levels and structural cues to find information. It is generated by the browser from the DOM (Document Object Model) tree and accessed via platform‑specific Accessibility APIs.

The DOM contains objects representing all markup elements, attributes, and text nodes. That’s why following a proper heading hierarchy (h1, h2, h3, …) is crucial – skipping heading levels cuts off branches that assistive tech needs for a sound climbing route.

NVDA vs JAWS

The table below (from our workshop at We Are Developers 2024) shows how two popular screen readers read the same content in the same browser, yet produce different output.

Testing setup

• NVDA 2024.1.0.31547 in Chrome v126.0.6478.127 on Windows 11 Enterprise
• JAWS 2022.2204.20.400 in Chrome v126.0.6478.127 on Windows 11 Enterprise

NVDA will say

“Choose your Starter Pokémon Table with 4 rows and 3 columns Choose your Starter Pokémon caption”

JAWS will say

“Table with 4 rows and 3 columns. Choose your Starter Pokémon. Column 1, row 1, person.”

Same table, same code, same browser – two different outputs. Neither is inherently better; both get the job done, but be aware of the nuances.

Which Screen Reader Setup Is Best for Testing?

Classic UX answer: it depends. Consider your target demographic and the operating systems you’re developing for.

WebAIM’s annual Screen Reader User Survey reveals the most common SR‑browser combinations. The latest survey (Dec 2023 – Jan 2024) is available at the Screen Reader User Survey #10 Results. While you’re there, also check the WebAIM Million report, which audited 1 million websites to benchmark accessibility progress and highlight common WCAG failures.

Screen Reader Testing Summary

• JAWS – 40.5% of primary desktop/laptop users
• NVDA – 37.7%
• VoiceOver – 9.7% (3rd place)

The three dominant browsers for screen‑reader users are Google Chrome, Microsoft Edge, and Mozilla Firefox.

Results for primary desktop or laptop screen reader use – source: WebAIM Screen Reader Survey #10.

Results for browser usage with primary screen reader – source: WebAIM Screen Reader Survey #10.

Offline Navigation

The White Cane

The white cane is an iconic, reliable tool for obstacle detection. It senses floor texture, drop‑offs, and stairs in both directions. Many assistive‑tech startups try to replace it, but after two weeks at Hope Tech Plus I discovered that nobody who uses a white cane actually wants to give it up.

That said, the cane isn’t a universal solution. Carrying it all day can strain the wrists, and bumping into obstacles can be painful for people with joint issues. Some users prefer alternative techniques, such as guide dogs.

Guide Dogs

Guide dogs are the “four‑pawed part of a guide pair.” Training takes 18 months to 2 years and includes socialization, basic obedience, and keyword training for everyday actions. The most popular breeds are Labradors, Golden Retrievers, and German Shepherds due to their temperament, size, and trainability.

A dog must focus exclusively on its handler, ignoring distractions like food, other people, or loud noises, while staying vigilant for obstacles. According to the International Guide Dog Federation, about 23 000 guide dogs are on active duty worldwide. Most work up to age 10, though this varies by pair.