A study of the interrelationship of the bacteria recovered from both eyes of 410 patients awaiting surgery revealed that bacteria of a given type were from two to ten times more likely to be cultivated from one eye if they were present in the fellow eye. Organisms cultivated from lid-margin material were found in only one half of the corresponding conjunctival sacs, but organisms recovered from conjunctival sacs were nearly always found on the corresponding lid margins. Staphylococcus and S albus seemed to have a negative influence on each other.
Allansmith MR, Ostler HB, Butterworth M. Concomitance of Bacteria in Various Areas of the Eye. Arch Ophthalmol. 1969;82(1):37-42. doi:10.1001/archopht.1969.00990020039009