In view of the possibility to obtain indirect information on the interdependency between brain tissue metabolish and the diameter of the intraparenchymatous arterioles through measurement of systemic blood gases and blood pressure on one hand and the diameter of the central retinal artery on the other, we describe a modified method of fundus photography which is practical for neonatologists owing to the simplification brought about by the use of a special contact lens. In an appendix the relevant optical data are analyzed. Fundus photographs of neonates suffering from cardiac malformation or asphyxia are shown.