The evaluation of diabetic retinopathy is often difficult, because the clinical picture is complex due to the mUltiplicity of symptoms. Omission of treatment by photocoagulation at the right moment may have grave consequences. Forthe evaluation of diabetic retinopathy we have to estimate first the developmental degree of each symptom and secondly we have to estimate what the natural history of each particular retinopathy will be. There exists a number of classification systems, into the frame of which the clinical picture of diabetic retinopathy can be placed. Without entering into the details of these systems we want to mention that our classification has been developed from the method of Oakley and the classification model conceived at the Airlie House meeting in 1968. The essence of this classification is that standard pictures are used for the estimation of the developmental degree of the different symptoms in diabetic retinopathy. In our classification we use for each symptom two standard photographs instead of one, as originally proposed at the Airlie House meeting. (1,2). Standard photograph number one stands for the moderate (grade 1 ) manifestation and standard photograph numbertwo stands forthe marked (grade 2) manifestation of the symptom. Ifthe manifestation ofthe sympton is less marked than in standard photograph one, it is referred to as < 1 ; if it is more marked than in standard photograph two, it is referred to as > 2.