An important aspect of the ophthalmologists’ work is the examination and therapy of eye movements. For the comprehensive examination of eye movement and eye movement control the three-dimensionality of the ocular muscle apparatus must be taken into consideration. For this purpose, the Der Chronos Eye Tracker (C-ETD) hat sich für diese Zwecke in zahlreichen Untersuchungen bewährt.

The use of refractive surgery (e.g. Lasik operation) for the correction of vision demands precise realtime measurement of eye position. Accordingly, throughout each laser operation the position of the operated eye is measured by a videooculographic eye tracker and relayed to the laser guidance control. Thus, the laser firing pattern is compensated for any changes in eye position.

For this purpose CHRONOS VISION operates as an OEM, currently delivering the OneK+ Eye Tracker with a measurement rate of 1000 + Hz and equally critical, an extremely short latency (< 1 ms) for this realtime task.

CHRONOS VISION has also developed additional software solutions for robust and precise eye tracking, including gaze/vertical and horizontal eye rotation, z-distance and eye torsion. These algorithms are integrated into the DeyeRECTOR ^® concept.

It has been maintained that the eyes reflect the soul. In this sense the examination of eye movements often provides useful information in the diagnosis of numerous diseases of the brain and the nervous system.

Since its founding in 1998 CHRONOS VISION has cooperated closely with the Vestibular Research Lab at the Charité Medical School Berlin. Prof. Clarke, as head of the research lab, has worked with neurologists, ophthalmologists and psychologists for over 25 years and participated in a wide variety of research and clinical studies involving eye movements.

The design and functionality of our medical devices reflect the experience and knowledge gained in this scientific work.

CHRONOS VISION manufactures and distributes medical devices and systems for the measurement and analysis of eye movements, which are certified according to the European Medical Device Directive (CE-MDD). These provide the clinician with an objective basis for the differential diagnosis of many neurological disorders.

Our activities in this field include:

• Development of algorithms for precise measurement of three-dimensional eye movements
• Novel techniques for the measurement of eye and head movements
• Software packages for the clinical testing of the vestibular and oculomotor systems
• Manufacture of CE-MDD certified Scleral Search Coils (SSC) for the precise measurement of two- and three dimensional eye movements.

For the specific requirements of clinical labs for vestibular and oculomotor testing CHRONOS VISION has carried out pilot developments for OEM customers, e.g.:

• DC electrooculography preamplifier as backup solution for those cases where VOG is not feasible (e.g. with patients with strong corrective spectacles).
• Compact, head mounted device for the measurement of the Subjective Visual Vertical (SVV). This test currently represents an important aspect of vestibular diagnostic examination. For further information about the Subjective Visual Vertical we recommend the following clinical study:
  Schönfeld U., Clarke A. H. – 2011: A Clinical Study of the Subjective Visual Vertical during Unilateral Centrifugation and Static Tilt ; Acta Otolaryngol 131(10):1040-50
  

Measurement of eye movements plays an important role in the research of spatial orientation, balance and sensory motor coordination. In addition, eye trackers are widely used in numerous psychological studies, in particular in the area of human factors.

The eye trackers manufactured by CHRONOS VISION are in use worldwide in clinical and research institutes and have been deployed on the International Space Station and in the research labs of the Russian and US American space agencies.

Further developments include pilot projects:

• High speed eye tracking during functional MRI
• Wireless VOG for bedside examination and sport activities
• Eye and head coordination studies in animals