The ability to measure intraocular pressure in rodents is very important for the advancement of glaucoma research. This review article describes various currently used methods, such as, microcannulation, servo-null micropipette, Tonopen tonometer, rebound tonometer, Goldmann applanation tonometer, Schiötz indentation tonometer, pneumatonometer, and optic interferometry tonometer. Their principles of operation, advantages and limitations, as well as a calibration method are also discussed.