Eye rinsing is the major therapeutic measure with a decisive impact on prognosis after chemical or thermal eye irritation. Several different major targets are addressed by this measure.Up to now emphasis in research was placed mostly on the neutralisation of chemical products. Newer experimental results on the basis of biological experiments interpreted against the background of basic chemical reactions may enhance clinical treatment by introducing new mechanisms of intervention.Experiments on the modification of osmolarity, buffering capacity and solubility products show new possibilities of therapy in eye rinsing after eye irritation. These mechanisms are demonstrated by means of key experiments.The official recommendation of rinsing a burnt eye with water seems to be insufficient against the background of actual experimental data. Measurements of pH after eye burns indicate no buffering effects for water, or aqueous saline solution. There was weak buffering for phosphate buffer in alkali burns and a high capacity for neutralisation for diphoterine in alkali and acid burns. Ionic contents and osmolarities of the rinsing solutions have a decisive influence on the ionic composition and osmolarity of the burnt cornea after rinsing. Cellular damage is enhanced in unaffected healthy cell cultures by hyposomolar rinsing.We recommend buffered solutions with high buffer capacities for initial eye rinsing. The advantage or disadvantage of the elevated concentration of ions in the buffered rinsing solutions determining osmolarity cannot be confirmed or refuted up to now. It seems to us to be certain that osmolarity is a decisive future factor in initial rinsing.