Ko te Resin he matū matū me te hanganga phenolic. He marama te taumaha o te arotahi Resin, he nui te pāmahana, he kore ngawari te pakaru, he pakaru hoki kaore he tapa me nga kokonga, he haumaru, ka taea te aukati i nga hihi ultraviolet, ko te kapia he momo mohiti tino pai mo te hunga myopia i tenei wa.