Added some words to specify required contrast ratios.

diff --git a/docs/pages/accessibility.md b/docs/pages/accessibility.md
index 2bf56adb457fb00115beb8d07c6c2f201f0d4097..126c72e75886e6ff1b3e7cbc2e6b16dbb4633e9f 100644 (file)
--- a/docs/pages/accessibility.md
+++ b/docs/pages/accessibility.md
@@ -22,7 +22,8 @@ Aside from accessibility features that has been built into Foundation's componen
 
 ### Visual
 
-Visually-impaired users may have low vision or be completely blind. For low vision users, proper typographic contrast is important, both size and color. Foreground colors should stand out from background colors. Blind users consume the web by reading it using a [screen reader](http://en.wikipedia.org/wiki/Screen_reader). Screen readers read the content of a web page out loud, or write it out as Braille, using certain queues from the HTML to infer meaning.
+Visually-impaired users may have low vision or be completely blind. For low vision users, proper typographic contrast is important, both size and color. Foreground colors should stand out from background colors. You can use tools to calculate the contrast ratio of your foreground and background colors. The contrast ratio should at least be 1:4.5 for normal text and 3:1 for large text.
+Blind users consume the web by reading it using a [screen reader](http://en.wikipedia.org/wiki/Screen_reader). Screen readers read the content of a web page out loud, or write it out as Braille, using certain queues from the HTML to infer meaning.
 
 ### Motor