Perimetric ophthalmic instrument using light diodes - of controllable luminous density and with light diode fixation point

摘要

The perimetric ophthalmic instrument has a semi-circular viewing surface (2) inside which is arranged a fixation point (4) as well as a number of groups of switchable light sources (3) of small surface area whereby the light sources are light diodes. Pref. the electrical current supplied to the light diodes is regulated with the aid of a simple control resistance thus controlling the luminous density. The luminous density of the light diodes (3), distributed over the surface, increases from the centre of the viewing surface outwards. A light diode also serves as fixation point (4) and different coloured light diodes can be used as an additional colour test.