[Effect of various stimulation filters on tear film breakup time]

The tear break-up was determined in 30 patients with healthy eyes aged from 18 to 67 using two different types of filter combinations: (1) Schott Filter OG 530 and Schott Filter BG 12. (2) Schott Filter OG 530 and Zeiss Filter 485. In view of the filter characteristics, we expected a reduction of the variance of the tear break-up time with the second filter combination. This did not occur. There was no difference between the two filter combinations described according to the Wilcoxon Test on the 5 percent level. The reasons are discussed.