Rett syndrome is a progressive neurodevelopmental disorder, named after the Austrian doctor who first described it, that almost exclusively affects girls and severely impairs their ability to communicate.
The disorder is caused by a gene mutation and is characterized by microcephaly, loss of communication, stereotypical hand movements with loss of their function, ataxia or loss of muscle coordination during voluntary movements, apraxia or the inability to perform meaningful, previously learned actions, behavioral difficulties with symptoms from the autistic spectrum, intellectual disabilities, and very often epilepsy.
The syndrome has four stages of development, and the second stage leaves the greatest damage to the ability to communicate. During this phase, speech communication and the performance of movements suffer more and more, which makes communication progressively more difficult.
That is why assistive technology devices are of great use to people suffering from Rett's syndrome as a tool for breaking into the world that they do not stop experiencing, but it is increasingly difficult for them to communicate with it.
Selection of assistive technology according to user needs
The ability to combine communication modules with eye tracking technology in  Tobii Dynavox products  has proven to be very useful for users with Rett syndrome in learning communication skills. They have proven to be the most useful in case of loss of motor skills, reduced fine motor skills and loss of voluntary hand function and numerous involuntary movements.
Tobii Dynavox's advanced eye tracking devices are easy to adjust and easily compensate for involuntary head movements that could affect their performance. Various assistive technology devices and solutions from Tobii Dynavox's diverse range of manufacturers can ease many communication difficulties and barriers.
As the user develops his skills, so does the selection of communication tools and the number of their different features.
Rett syndrome research and eye monitoring
Without the ability to track the eye, there would be very few tools for quality research on the cognitive abilities of patients with Rett syndrome. Many tests often rely on the ability to verbally communicate and use motor skills. This is exactly the problem with this syndrome, which automatically loses two important sources of feedback.
In one study conducted at Montefiore Children's Hospital in the USA, a comparison was made between children with Rett syndrome and a control group of patients. With the help of eye-tracking technology, an analysis of gaze focus on different images was made in patients with Rett syndrome and a control group of patients. This research confirmed a whole hidden world of girls who understand much more than they manage to say and show to the world around them. In this case, eye-tracking technology has helped to understand the minds of those who are unable to express it to us.
When researching this syndrome, assessing and monitoring patients, these tools can be used by experts, teachers and parents. Gaze Viewer is one of them . It is a tool for assessing the user’s cognitive abilities that creates a video with a screenshot showing where the user was looking and how his gaze moved. This data can be saved as individual images or movies and used to generate reports to assess eye tracking, content comprehension, and various other tests.