The device can take more measurements in relation to vision than conventional devices. Measurements: Visual acuity, vergence, image formation, clinical measurements of visual acuity, equivalence of measurements, screening of visual acuity in OSH, contrast, illumination, visual performance, signal detection theory, visual performance in the elderly, lenses for presbyopes. At the same time, various existing deficiencies are rectified and the user interfaces are customised according to the customer's specifications. On the basis of the measurement results, further values are calculated using complex formulae and displayed graphically. Development of the interfaces to the test system (hardware), implementation of the calculation models, execution of the analyses. Realisation of customer requirements, corrections and extensions with Microsoft C++. Testing and documentation (technical).