Some of the 92FS models came with three dot sights, and some came with the plain notched rear and white dot front sight, depending on production run, year made, etc. .

yes it was made that way on some 92FS models

The rear sight has been replaced. It is easily remedied. Buy a replacement sight. These are usually called 3 dot sights. Have a good smith replace the existing rear sight. These can be really tight and you do not want to damage the slide.

Roger, yes, there was a model 92FS that had the Black dot less horizontal ridged rear sight. I have seen it at a gun show a few years back but, it was new at the time.