The Binocular Vision Analyser is a tool designed to be used by Orthoptists, Optometrists,  Ophthalmologists and other eye care professionals, for assessing ocular motility and binocular single vision.

The Hess Screen test works in the same way as a conventional Hess screen by measuring the dissociated deviation between the two eyes in various directions of gaze. This allows the clinician to differentiate between concomitant and incomitant deviations and determine which extraocular muscles are affected.  Using a computer to perform this test improves the accuracy of measurements and means that results can be automatically displayed and printed in a variety of formats, and stored for future reference.

The Field of Binocular Single Vision (FBSV) test replicates the test conventionally carried out using and arc on bowl perimeter, on the computer screen.

The Uniocular Field of Fixation (UFF) test uses a small optotype to measure the maximum excursion that each can make from the primary position by detecting a reduction in acuity as the target moves off the fovea when the eye has reached the limit of movement.

The system can be supplied as software only or as a complete solution:

Running the software on your own PC

The software will work on most PCs running Windows 7 or later.  The software works best with two monitors - one for the patient to view and the other to control the test.

The monitor viewed by the patient should be a good quality flat panel display or TV.  While the software will run on any size monitor, the larger the monitor - the larger the area of the field that can be assessed.  In practice, we recommend a minimum monitor size of 24’’.  To cover the equivalent area as a conventional Hess screen, a 48'' monitor or larger will be required. The software can also be used with a data projector which allows for a greater viewing distance / larger test area.

We recommend a 22'' monitor or larger for the control screen.

It is very important that the patient's head is not moved during the tests.  To achieve this, it is strongly recommended that a chin/head rest is placed at the required distance in front of the screen

The complete solution

The complete solution includes a bespoke instrument table, chin rest, 48'' television and touch-sensitive all-in-one PC as shown below.