heterochromia and the (color)_eyes tags

So I was recently adding tags to a certain image that was tagged with heterochromia and I noticed that it was also tagged with both blue_eyes and green_eyes and had only one of each so I went to change those tags from plural eyes to singular eye and was informed that neither of those tags existed. Dismayed I decided to look further into it and discovered that heterochromia is tagged on a lot of images which are also tagged with tags ending in eyes, even those that only depict one person and thus can only have one eye of each color. The question I get out of all this is why is this the way it is? Is this site so averse to being specific that we should ignore it when the tags we have placed on an image don't actually fit and in fact can't fit because of their very definition? I ask for the creation of new tags that will better fit the actual content of the images under the heterochromia tag (aka blue_eye red_eye green_eye etc) and that they be blanket applied to all the images that already contain a tag for eyes of the same color that have been marked as only containing one person.

What you want can already be found under heterochromia blue_eyes or heterochromia red_eyes. There's no need for individual eye colors when that search is correct 99.9% of the times.

We generally don’t have singular and plural tags for the same thing because it’s considered (mostly) irrelevant for tagging purposes and would bloat the amount of available tags on the site. Not to mention that it would be annoying having to count every single thing you want to tag. It would be even more annoying to search for if you have to run different searches for one rock, two rocks, three rocks, four rocks… if you just want an image with some friggin’ rocks in it. Therefore, we usually use singular tags, e.g. rock, which means that at least one of that thing is in the image.

Why do we tag eyes as plural instead of singular then? Because eyes almost always come in pairs of two and characters with heterochromia or cyclops are quite rare. Thus, a tag like red eyes actually means “there are one or more red eyes in the image” and there’s no need for a red eye tag.

Can this be confusing? Yes. Is it still the more practical solution? Yes.