This is a modern device which is mainly used to determine the sharpness of vision. It works as a digital board displaying symbols which are the same size in the individual rows, but the rows are of varying sizes – they get smaller as they go down. They symbols may take the form of letters, numbers, pictures or symbols. A patient without any sight impairment should be able to recognise symbols of a certain size without any great difficulty.
This digital LCD optotype also enables the performance of a wide range of specialised optometric and stereoscopic tests (Snellen, Landolt circles, numbers, letters, symbols for children, monocular tests, binocular tests, colour perception, astigmatisms, 3D tests, the Maddox test and others).