From a straight-ahead view of 0 ° when screening the field of vision at a distance, up to a test field at a distance of 25 cm for reading, tilted by 38 °, the test subject can use the rotary knob to set the optimum test field inclination for his vision aid and the distance tested.
Preiskovanec lahko z vrtljivim gumbom nastavi optimalen naklon testnega polja za pregled vida in testno razdaljo. To zajema vse od ravnega pogleda pod kotom 0° pri pregledu vidnega polja na daljavo do testnega polja na razdalji 25 cm za branje, nagnjenega za 38°.