Levels of lacrimal proteins, 90% of which are synthetised by the lacrimal gland, normally vary between 2.5 and 6 g/litre. Three fractions migrating towards the anode may be isolated by electrophoresis: 2 prealbumins corresponding to approximately 30% of the proteins, a poorly known group (4 to 12%) and lactotransferrin (40 to 50%). One fraction migrates towards the cathode: lysosyme (25 to 35%). It is also possible to demonstrate a protein profile of tears (albumin less than 200 mg/l, transferrin less than 20 mg, IgA 100 to 200 mg/l, IgG less than 10 mg/l, bacteriolytic activity equivalent to a concentration of lysosome of 4 to 6 g/litre). In pathology, electrophoresis is valuable in the study of dry syndromes and for identification of fluid from a palpebral cyst. The protein profile is of interest above all when the tears are inflammatory.