In this paper we give a review of the Bowen fluorescence survey, showing that narrow emission lines (mainly N III and C III lines between 4630 and 4660 A˚) appear to be universally present in the Bowen blend of optically bright low mass X-ray binaries. These narrow lines are attributed to reprocessing in the companion star giving the first estimates of K2, and thereby providing the first constraints on their system parameters. We will give an overview of the constraints on the masses of the compact objects and briefly highlight the most important results of the survey. Furthermore, we will point out the most promising systems for future follow-up studies and indicate how we think their estimates of the component masses can be improved.