[Investigation of mesopic vision and sensitivity to glare by means of the new "nyktometer" (author's transl)].

In addition to photopic visual acuity both mesopic vision and sensitivity to glare play an important role in road traffic safety. It is known since the comprehensive investigations by Harms and Aulhorn that mesopic vision and sensitivity to glare are subjected to interindividually different changes with increasing age. 350 persons divided into three age groups were tested with a recently developed "Nyktometer" in order to gain some information about the influence of age on mesopic vision and sensitivity to glare. The results clearly show that both mesopic vision and visual performance in the presence of glare are strongly reduced with increasing age.