This dissertation has three cornerstones:

• Haptics
• Human-Computer Interaction (HCI)
• Blind Users

Haptics deals with controlling human movements and getting feedback through the sense of touch. A haptic interface transmits forces to a person’s hand or fingers in a way that mimics the sensation of touching real objects. Virtual haptic touch can be particularly useful for people with visual impairments. It makes it possible for a blind person to touch virtual objects, corresponding to the way a sighted person can see objects on a computer screen.

The goal of this research was to carry out an unbiased investigation of the potential of this technology for blind people. The more specific aims were to:

• Investigate if and how blind people’s computer usage can be improved by virtual haptics.
• Investigate the problems that arise with graphical user interfaces for blind people and how these problems can be managed with haptics.
• Develop new applications and find new areas in which virtual haptics can be applied for blind people.

The design process has been primarily influenced by theories of usability engineering and reflection in action/reflection on action, focusing on the role of the engineer-designer. A concerted effort is made to use technology as a language to communicate with the users.
Several haptic interface devices have been involved. The Phantom from SensAble Technologies has been used the most. It is a small robot with a thimble or stylus attached to the tip which supplies force feedback to the user. The others are the FEELit Mouse from Immersion and the force feedback joysticks from Logitech and Microsoft.
Eighteen test applications were developed over five years’ time. They included games, curves, textures, drawings, menus, floor plans, and geometrical objects. Formal and informal user tests were performed on blind, blind-deaf and sighted people.
One of the key results presented are five guidelines for non-visual haptic interaction design for researchers, designers, testers, developers and users of such applications. The guidelines are:

• Elaborate a virtual object design of its own
• Facilitate navigation and overview
• Provide contextual information
• Utilize all available modalities
• Support the user in learning the interaction method and the specific environments and programs

These guidelines represent the filtered and condensed knowledge and experience that the Haptics Group at Certec has gained during the testing and development process. They are further delineated and are a complement to existing HCI guidelines.
This work shows that there is great potential in using haptic technology in applications for blind people. It is viable to translate both 2D and 3D graphical information and make it comprehensible via haptics. It has been demonstrated that a blind person can orientate and navigate in a virtual haptic environment and that these tasks can be further supported by using complementary information such as sound and Braille. It is also possible for a blind person to use knowledge gained in the virtual world for real life orientation.