How to make your awesome website EVEN MORE AWESOME by making it accessible

Part 0: Introduction
Whenever feasible, try to design a website to be usable by as many people as possible.  This can include people who cannot see, or hear, or move their mouse well, or even at all.  Here are some hints and tips for accessibility-aware web design.

Step 1 Part I: Visually Impaired Folks

First off, remember that not all visually impaired folks are blind.  Some need high contrast color schemes, some are color blind, others can use the monitor with very large (or zoomed) fonts.  And some are fully blind, with no way to directly use visually displayed content.

This section is larger than the other two, because web pages are primarily a visual medium.

1. Does your web site make assumptions about how people are going to be looking at your site?  Try looking at your web site with large fonts set in your browser.  Make sure any non-text visual elements (buttons, images, etc) also scale.  Try setting a high contrast color scheme.  Still usable? 
Good!

Did you specify a specific font size, rather than relative size? 
Bad! 
Use a percentage of the default font size in your "font-size" style sheet stylings.

Comments

[mg0930mg]

:( I can not see the number.

[regisd]

The number in the image for step 1?  It's one of the standard Ishihara color plates for testing for colorblindness.  http://en.wikipedia.org/wiki/Ishihara_color_test has more details.

Have you been tested for colorblindness?  Something like 5-10 percent of the population has some kind of colorblindness.

[mg0930mg]

Yes, I have taken the colorblidness tests in school since first grade, and yes, I am colorblind. I was most likely going to be colorblind. On both sides of my family, all the guys, and some of the girls are colorblind.

[cekpi7]

i can see colors but i cant read number :P since third grade i think

[mg0930mg]

Then you are colorblind...?

[Shoukei]

These could really come in handy especially those with dyslexia like me. :P

[merijnvw]

 Thanks for sharing, these are some useful tips as I always wanted to make my websites accessible for the visually impaired.
you have my vote

[kelseymh]

Thank you!  In addition to the Section 508 stuff at Usability.gov, the W3C also has some execellent resources for accessibility in their Web Accessibility Initiative (WAI), a core component of their "Web For All" principle.

On a side note (and a bit of vanity), this is a soap-box I've been shouting from since the Web began...

[regisd]

You're quite welcome.  Computer accessibility issues are a pet peeve of mine.  Computers can make it much easier for people with disabilities (or even temporary injuries) to get the information and other content that they want, but only if designers design for it.