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Re: Low Vision and CSS (The EM is not enough)

From: Peter Verhoeven <pav@oce.nl>
Date: Thu, 04 May 2000 10:00:31 +0200
Message-ID: <39112E1F.D6D4D3B@oce.nl>
To: "Leonard R. Kasday" <kasday@acm.org>
CC: w3c-wai-gl@w3.org, w3c-wai-er-ig@w3.org
Hi Len,

Yes! Good point. I see that on many pages. On some pages with tables the
text is under the image if a the user sets a large font.

Most of font size and table witdh conflicts are the cause of problems
low vision have with reading pages on the Internet. Maybe browser
developers could introduce options like "Loading table column in new
window" or "loading table cell in new window" or "Disable JavaScript if
a page in a frame is loading in a new window"?

Regards Peter Verhoeven
Internet : http://www.magnifiers.org (The Screen Magnifiers Homepage)


"Leonard R. Kasday" wrote:
> 
> To WCAG
> Copied to ER
> 
> People with low vision often increase the default font size.  One might
> think this could be accommodated by using em units instead of absolute
> units, but that doesn't appear to be the case.  If you look at
> 
> http://astro.temple.edu/~kasday/wai/css-em.html
> 
> using Internet Explorer 5, with medium font size, and a window
> approximately a screen width, you'll see a paragraph at the top and text
> below it.  The lower text is positioned with respect to the window with
> ems.  However, if you now make the window smaller, you'll see the text in
> the top paragraph wrap, causing the number of lines to increase and it will
> eventually overlap the text below it.
> 
> Similarly, if you make the font bigger using View->font size, you'll again
> get the overlap.
> 
> The moral is that, checkpoint 3.4 to use relative units such as the EM is
> not enough.  There needs to be a more general guideline that pages shall
> read sensibly when default font is made larger.
> 
> For convenience, I've included the text of the referenced example in this
> email.
> 
> Len
> 
> p.s.
> Presently, this example works only in MSIE 5, not Opera 3.62 or Netscape
> 4.7.  I think MSIE is doing it right.  CSS gurus please check...
> 
> ==========
> 
> This shows that text can overlap even when using ems. If you make screen
> narrower or font larger the text will overlap... at least in Microsoft
> Internet Explorer 5.0 (Overlap does not occur in Opera 3.62, and Netscape
> Communicator doesn't show it at all).
> This sentence starts out below the first one.
> 
> Len Kasday, kasday@acm.org, Pennsylvania's Initiative on Assistive
> Technology, a program of the Institute on Disabilities/UAP at Temple
> University
> --
> Leonard R. Kasday, Ph.D.
> Institute on Disabilities/UAP, and
> Department of Electrical Engineering
> Temple University
> 423 Ritter Annex, Philadelphia, PA 19122
> 
> kasday@acm.org
> http://astro.temple.edu/~kasday
> 
> (215) 204-2247 (voice)
> (800) 750-7428 (TTY)
Received on Thursday, 4 May 2000 04:02:04 GMT

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