The study of eye movements is an important source of information for researchers (eg neurobiologists, psychologists and optometrists) and healthcare professionals (eg neurologists, ophthalmologists, ear-nose-throat doctors, orthoptists). Research has shown that the study of eye movements is a powerful tool for understanding how our psyche and our brain work. Understanding all eye movement disorders is still a challenge, which is why further knowledge is needed about the underlying disease mechanisms and new techniques to better measure and characterize eye movements. Eye movement disorders are a common disease and affect over 3% of the Swedish population, probably many more. It is therefore a common disease condition at eye clinics. They are often the initial manifestation of disease affecting the central nervous system. Therefore, it is important that we develop methods to measure eye movements, to facilitate diagnosis, so that treatment can be started as soon as possible and prevent various complications that affect the body's functions. This research project is about describing disease states that affect the eye movement system and developing methods so that a diagnosis can be made early when the patient comes into contact with healthcare.