There are two tags that seem to be referring to the same subject:
Should we merge these? If I remember correctly from the previous discussion, we decided to drop the "computer" prefix for these tags.
I am not sure of what the guidelines are for naming tags, but here are my 2 cents. As far as I have seen, this area is generally formally referred to as Computer Vision, and not Vision. Most courses and book names use Computer Vision. The Wiki article is titled Computer Vision. One can even see the use of Computer Vision in questions from students, such as this.
Keeping the computer-vision tag offers the additional benefit that when searching for the tag when asking a question, if the user starts typing "vision", he will still be shown the "computer-vision" tag in the suggested tags (search looks for matching tag substrings), while someone typing "computer-vision" would also be shown the right tag in the suggested tags, though it may take longer to show up.
I guess dropping the "computer-" prefix makes sense in that the prefix is redundant on a CS site. But I still feel that computer-vision might be a better option. Of course, on the issue of merging of tags, please go ahead. Which one needs to be kept is the question.