Tear Strips
One of the diagnostic tests that is used for dry eye is placement of a paper strip in the eye. The idea is that the tears soak into the strip and along the strip, so the length of the strip that is soaked indicates something about tear quantity.
In the May 2024 edition of the journal Cornea, Dr. M. Teresa Magone and Dr. Peter Schuck published a study that found that there was a lack of standardization among different brands of strips. They proposed some possible solutions to help interpret results, but, to me, this study reinforced my previous inclination that the use of these strips is not that helpful.