Several organisations have developed simulations which illustrate some of the barriers that may impact on accessibility and ease of use. Simulations cannot give true representations of disability, but can promote discussions around the subject - it is important to know when and how to use simulations.  The Braille Institute in California have developed a mobile App and WebAim host a series of webpages along with others offered on this page. 

Braille institute logoVisionSim: iPhone, iPad and Android App

Braille Institute's VisionSim© FREE app for smartphones was designed to foster understanding and compassion for the millions of people affected by leading eye conditions. Using touch-screen controls, the user can select one of the four simulators to replicate the symptoms of that particular disease. The application uses the camera in the iPhone or Android to allow the user to see the world through digital filters simulating the symptoms and experience of the disease. Using sliding touch-screen controls, the user can manipulate the severity of the symptoms. The real-time still images can be saved by the camera and stored for later review, or to be shared.

VisionSim© was developed to allow people with healthy vision to experience the world through the eyes of a person experiencing one of nine degenerative eye diseases, including macular degeneration, diabetic retinopathy, glaucoma and cataracts. Download VisionSim for Apple iPad and iPhone or download the Google Android version.

WebAIM logoWebAim have a series that show the impact of certain designs and web services on users.

WebAIM: Screen Reader Simulation This simulation provides a way to experience what it is like to use a screen reader. A web site, the University of the Antarctic, is presented as a screen reader user would experience it. Keyboard shortcuts are provided to navigate within the site and find specific pieces of information.

WebAIM: Distractibility Simulation This simulation demonstrates how difficult it can be to navigate even a simple site when operating under an intense cognitive load.

WebAIM: Speed Read muddle text You are given 60 seconds to read a paragraph aloud. The letters in this paragraph are reversed, inverted, transposed, and spelling is inconsistent. There will be two questions to answer at the end of the 60 seconds, so you must decipher the words as best as you can sovaldi price in india. Although this simulation is related to Dyslexia, it provides an example of the frustration that can arise when it is hard to read at speed and difficulties impact on memory. 

WebAIM: Low Vision Simulation This simulation provides an opportunity for users to experience a web page using simulated visual disabilities. While it certainly does not simulate low vision itself, it can be used to help understand how visual disabilities can impact web content and how web content can better designed.

Coblis - Colour Blindness Simulator "If you are not suffering from a colour vision deficiency it is very hard to imagine how it looks like to be colour blind. The Colour BLIndness Simulator can close this gap for you. Just play around with the sample picture or upload your own images. Please make sure that you just use JPG, GIF or PNG images with a size below 600kB." (Daniel Flück, 2007)

Web Page Backward Compatibility Viewer ( "Want to see if your page would be usable without tables, scripts or style sheets? Visit this site, enter the URL of your page, and check only those features that you want the browser to be able to see. This site is meant for checking if your pages would be usable with older web browsers, but it can also be used to simulate common accessibility issues. For example, turn off images to see your ALT text in place. Turn off tables to see what order text would appear in without the table, a good indicator of how usable the page might be to someone using a screen reader. Or, turn off style sheets to see if someone who uses their own style sheet to compensate for low vision will still be able to use your page." York University, Toronto Web Accessibility testing pages

ACTF aDesigner - It was originally known as IBM aDesigner and 'includes simulation modes to present how Web pages might be viewed by users who are blind, color blind or have low vision Promotes early awareness of potential accessibility and usability issues Checks site for compliance against established accessibility guidelines Includes a site-wide analyzer with graphical features'.