ABSTRACT Hands-free interfaces could ,be the ,best choice ,for Human- Computer Interaction (HCI) for people with physical disabilities that are not capable of using traditional input devices. Once a first prototype,is developed ,in the ,laboratory taking into account design and usability requirements, real users is what finally categorize an interface as useful or not. Therefore, an evaluation
... [Show full abstract] ofour,interface with users with cerebral palsy and ,multiple sclerosis has been carried out during a project of 9 months,long. This paper presents a vision-based ,user interface designed ,to achieve computer ,accessibility together with the validation and evaluation of its ,human ,computer ,interaction issues such ,as usability and accessibility. Categories and Subject Descriptors H.5.2 [Information Interfaces and ,Presentation]: User Interfaces – input devices and strategies; K.4.2 [Computers and Society] – Assistive technologies for persons with disabilities General Terms