Lethata optima is a moth of the family Depressariidae. It is found in Peru.[1]
The wingspan is about 34 mm. The forewings are greyish overcast with reddish brown especially in the anal area and with the costa narrowly ochreous. The termen is ochreous with a purplish spot at the end of the cell with scattered white scales. The entire wing with scattered fuscous scales. The hindwings are whitish overcast with grey.[2]