Computer Simulation of Visual Impairments

Introduction Screenshots User Guide Project Report Links

User Guide

The project provides an interactive simulation of the symptoms of the visual impairments: myopia (short-sightedness), hyperopia (long-sightedness), glaucoma / retinitis pigmentosa (tunnel vision), macular degeneration, diabetic retinopathy, hemianopia, cataracts and colour blindness. See the homepage for more information and screenshots.

Source Code and Executables

The simulation is written in C and uses the OpenGL graphics library. The source code and executable for the simulation are available a zip file. The simulation was designed using Windows XP but should be compatible with older versions of Windows and other operating systems such as Linux where the OpenGL and GLUT graphics libraries are installed. The Windows executable simulation.exe uses the OpenGL dynamic link libraries opengl32.dll and glut32.dll. For more information about OpenGL see

Simple Paint Program

The simple paint program is written in OpenGL and has a GLUT interface. It has been integrated into the simulation of visual impairments to provide a . The current drawing tool is selected by clicking a button on the toolbar at the top of the screen using the left mouse button. A shape is drawn by clicking points on the screen for each vertex. 

Simple Paint Toolbar

Popup Menu

Layout of the Popup Menu

A popup menu is attached to the right mouse button and provides options to change the type and severity of the current impairment and the mode of operation.

Keyboard Shortcuts

Home Key - Move the Centre of Vision to the centre of the screen.
Up Arrow - Move the Centre of Vision up.
Down Arrow - Move the Centre of Vision down.
Left Arrow - Move the Centre of Vision left.
Right Arrow - Move the Centre of Vision right.

F1 - Normal Vision
F2 - Myopia (Short-Sightedness) / Hyperopia (Long-Sightedness)
F3 - Glaucoma / Retinitis Pigmentosa (Tunnel Vision)
F4 - Macular Degeneration
F5 - Diabetic Retinopathy
F6 - Hemianopia with Macular Involvement
F7 - Hemianopia with Macular Sparing
F8 - Cataracts - Cloudy Vision
F9 - Cataracts - Double Vision
F10 - Cataracts - Yellow / Brown Vision
F11 - Colour Blindness

1 - Very Low Severity
2 - Low Severity
3 - Medium Severity
4 - High Severity
5 - Very High Severity

Esc - Quit the simulation.

Centre of Vision

The simulations of glaucoma / retinitis pigmentosa, macular degeneration, diabetic retinopathy, hemianopia and cataracts allow the 'centre of the field of vision' to be moved around the screen. By default the centre of vision is tracked to the mouse cursor.

Stephen Ratcliffe. 2005

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