A significant difference in TF production was observed between subjects with a cataract (n = 72, 9.0 ± 7.3 mm/10 min) and those without ocular disease (n = 595, 14.4 ± 10.9 mm/10 min) (p = 0.0004, pairwise Wilcoxon rank sum test). Here, TF is linked to cataract.