There's a word. Raugs (yeast). From rūgt (get bitter, ferment). Derived as a thing that does the rūgšana. And the ū -> au is a typical pattern for such a derivation.
There's also the word raugs (thing to look at). From raudzīties (to look (with undertones of care, interest or usuality)). Derived as the object of the raudzīšanās. With the dz <-> g switch being a basic principle in the language.
And now, importantly. There's the word acuraugs. Someone you care deeply about, and who is a delight to see. Kind of how people call others the apple of their eye. And if you're being good about translation, maybe you just use that idiom.
Or you could say eye yeast.