tear production

Last reviewed 01/2018

• the normal volume of tears in the eye is 6 microlitres
• the turnover rate of tears in the eye is 1.2 microlitres per minute
• the composition of tears is similar to the electrolyte concentration found in plasma; tears are rich in proteins, particularly IgA; tears also contain beta-lysin and lysozyme (both of these substances have antibacterial properties)