It's tied to Eye Type. Either way, it's not going to be easy to change.
switch (e.eyeType) {
case GLOBAL.TYPE_ARACHNID:
t += " In addition to " + (o ? "your" : "[creature.hisHer]") + " primary two eyes, " + (o ? "you have" : "[creature.heShe] has") + " a second, smaller pair on " + (o ...