Which fits the DSC scene perfectly, and most other UT happenstances more or less adequately. Where it fails is VOY "The 37s", where Janeway speaks through the UT to a crowd that cannot be wearing UTs of their own, and everybody hears Janeway speak in their native language (English for most, but Japanese for one character). But DSC doesn't repeat the VOY feat (or should we say goof?) and merely goes with the "UT simply equates knowledge of the language" interpretation.
LaForge could have had replacement eyes in a heartbeat - he simply turned them down because he didn't want to downgrade from his vastly superior VISOR (see "Loud as a Whisper"). And the EMH made a new eye for Seven, who was a rather straightforward patient in only lacking said eye and not having damage to her optical nerve like LaForge.
Would it be difficult for somebody like Culber to make an eye for Detmer? Two decades later, McCoy can grow new kidneys bu giving the patient a single pill. And we never see him lament "If I only had (the ability to grow) a heart" in TOS, either. For all we know, new eyes are fairly simple to make in the 2250s already, but Detmer's damage is more extensive than that, as per the odd prosthetics covering quite a bit of her face.
Timo Saloniemi