ʻO nā puaʻa momi he ʻano puaʻa kūikawā, ke uhi ʻia kēia mau puaʻa me nā mea ʻokikene metala mai loko mai o ka ʻāpana mika.ʻO kēia mau puaʻa he hiʻohiʻona kiʻekiʻe ke aniani, ʻoi aku ka maʻalahi o ka mokulele a ʻoi aku ka maikaʻi o ka refractive co-efficient ma mua o nā puaʻa maʻamau.