Visually Impaired acess Web

The Net is revolutionizing how we access information. I wonder how the visually handicapped are impacted by this. Technology should help them access this beautiful resource. This thought occured when I was reading something on the 'captcha'  technique to prevent spamming.

More :
" Captchas based on reading text — or other visual-perception tasks — prevent visually impaired users from accessing the protected resource. However, captchas do not have to be visual. Any hard artificial intelligence problem, such as speech recognition, can be used as the basis of a captcha. Some implementations of captchas permit users to opt for an audio captcha. The development of audio captchas appears to have lagged behind that of visual captchas, however, and presently may not be as effective."

" A Screen Reader software application reads aloud information displayed on a computer monitor screen. The screen reader reads aloud text within a document, and it also reads aloud information within dialog boxes and error messages. Screen Readers also read aloud and menu selections, graphical icons on the desktop. Recent upgrades are much better reading aloud information on the World Wide Web. "

" What is a braille display ? [link]
A braille display is a tactile device consisting of a row of special 'soft' cells. A soft cell has 6 or 8 pins made of metal or nylon; pins are controlled electronically to move up and down to display characters as they appear on the display of the source system - usually a computer or braille note taker. Soft braille cells have either 6 or 8 dot pins depending on the model. Advanced braille code features 8 dot braille, but most will probably only use the 6 dot code. Dots 7 and 8, if present. can be used to show the position of the cursor in the text or for European 8 dot braille. They can also be used for advanced maths work and for computer coding. "