There are, as of this post, 3823 posts for white_sclera.
Having a lot of use of a tag isn't a problem in and of itself, of course, but in this case from a glance at the posting list for that tag it's mostly used for characters that normally have white sclera, which is more or less the normal thing for many animals in RL, with a bunch also used on monochrome images where the character's eye color isn't really obvious as far as TWYS goes.
Given the gross misuse of the tag, is there some automated way to clear out some of it? Off the top of my head I know of only two commercially produced characters whose normal model has non-white sclera, master_tigress (yellow) and renamon (black), but I'm sure there's quite a few fan/artist creations that would also qualify so just excluding the two named from a mass purge of white sclera seems like it would be a non-starter (if even technically possible, I don't know).
(Tangentially, though, does anyone really search on sclera color? :P )
Updated by Furrin Gok