usability test – How to test a website for visually impaired users?

Note: The reason I wrote this answer by pointing out the different checkpoints that a person must do to make sure his site is accessible to the visually impaired is because I think that a good understanding of the flaws or site design issues will help define the problems that users may be facing. by accessing the site

For starters, I highly recommend testing your website to see how it handles screen readers because it's about a base of potential users that you can not avoid and that you can not always assume that people could use magnification tools to read content in case of low vision and screen readers. are an accessibility tool expected not only for "blind" people, but also for people with limited vision. So, by avoiding them, you will technically alienate your own group of users.

That said, there are some best practices on what to do to ensure that visually impaired users can access your website.

Reduced visual acuity is probably the most well-known aging problem.
Yet, websites with tiny type are legion. Sites for seniors
should use at least 12 default fonts. And all the sites,
if they specifically target the elderly, should leave the users
increase the size of the text as you wish, especially if the default site is a
small font size.

  • Ensure consistency of design: Most older people usually know the standard colors of the links and would usually assume that an item of that color is a link. Avoid trying to implement new design colors for links and other active interaction elements. To quote the same report from Norman Neilson quoted previously

Hypertext links are essential design components; using a big text for
is particularly important for two reasons: 1) to ensure
readability, and 2) to make them more visible.
In addition, you should avoid tightly grouped links; using white space for
separate links decreases the erroneous clicks and increases the speed to
which users clicked on the right link. This rule also applies to the command
buttons and other objects of interaction, which should all be
big enough to make clicks easier

I also recommend taking a look at this Mashable article

Often, just a simple enlargement of the text to a user.
Consider offering alternative style sheets with larger font sizes and
make sure your layout does not break when text only zoom is on
the browser. Many visually impaired users will want to zoom in on
text without changing the scale of the full layout of the site, which can
cause difficulties in scrolling and tracking text over long lines.

Depending on the target market of your site, you can also consider:
increase the default font size by a few points, and if you publish
articles or large amounts of text, it's a good idea to propose
text versions only, so that the user can then manipulate the text but
he likes.

Use a sans serif font, such as Helvetica, not condensed.
Avoid using serif characters, novelty and display.

  • Use of color : Some colors may be difficult to anticipate for people with limited vision. There are also different types of color blindness and you need to make sure that the colors you select are understandable by people who are visually impaired or even color-blind. You can also use a color-coded simulator to see how your designs overlap, such as http://colorfilter.wickline.org/. Also make sure that the color contrast is significantly higher, so that users can read the content without having to force. this article of color combos

The use of appropriate colors can be an important element of usability.
for people with special vision needs. All monitors do not reproduce
accurately the colors you may have chosen for your web design. By
by staying in the 216 recognized "safe color selections for the browser", you
can be assured that the colors you choose will be transmitted without
change. This is important because some color combinations lose
their effectiveness when the level of contrast is reduced to
visually impaired viewers. The degrees of hue, lightness and saturation can
be less distinguishable, which can be a big problem,
especially if the colors are used as primary indicators.

By exaggerating contrasts or slight differences between the foreground
the background screen, the person with a visual impairment can
more easily differentiate colors. For the same reason, never use it
similar lightness colors side by side. Lighten the lights,
blue-green, green, yellow and orange and darken the dark colors, blue,
purple, purple and red for the most effective use of contrast. the
more radically different you can make each area, the more clarity
your web page will have.

By removing superfluous graphics and "busy work", you can unclutter your
website. A simple and clean layout is much easier to read and
navigate. Black and white design with minimal color added for
the focus is the best approach. Yellow, blue, white and black are the
colors less confusing for people with vision problems. In fact, while
it may not be the most appealing text, white or pale yellow text in 24 points
on a black background is considered the most readable color scheme for
users online.

  • Allow users to access your site with the help of the keyboardAlthough I know you mentioned that you do not want to support screen readers, I strongly dissuade you from taking such action. Also make sure your site can be navigated by keyboard, as this would allow users to quickly access content using keyboard shortcuts while also allowing. screen readers to scan the content. To quote this article from mashable

In addition to being useful to people with screen readers, the keyboard
Shortcuts can make website navigation for the visually impaired user far
Easier. With the addition of keyboard commands, it is possible to
navigate a site with the use of arrow keys and a few quick keystrokes,
eliminating the need to follow the mouse cursor on a screen – and
the associated need to continue to change visual focus. It can be a long time
way to reduce eye strain and frustration. Many users with visual
impairments surf the web on large screens (23 "or larger) that can
cause a lot of movement of the head and eyes, especially at a short distance
distances. The less time the user has to move to follow the cursor
(which can easily get lost) around the screen, the better it is.

In closing, here are some links that are worth the detour

Make your pages accessible to the visually impaired

WebAim: Understanding Blindness

5 tools to improve Web accessibility