Ranguemont Pass and Beaucedine Glacier are NOT the only places that the Lense can be obtained. A place where I constantly get the lense on my THF is in Castle Zvhal Bailey's. You know, home of DS(Dark Spark.) Plenty of ahriman's are flying around there. And they are easily SOLO'd at 75 on THF. Not sure if they link, but if you are going in a skill up PT, watch out for aggressive and linking Demons.
As a THF with Treasure Hunter II, I have killed a ton of eyes in Ranguemont Pass and Beaucedine Glacier, but haven't gotten a single lens. It's driving me crazy. >_<;;
I got one of these off a Bat Eye today in Beaucedine while doing mission 5-1. The little taru guy won't give me the quest (my fame is too low; see previous posts), and I don't do alchemy. Can't sell it at AH. I took it to Ensasa's Catalyst Shop in Windurst Waters; they offered me 148 gil for it. Despite not having much storage space, I guess I'll hang on to it until I have the necessary fame......Ironically, my fame is lowest in my home country :/
I must've killed 30 of these eyeball freaks in the pass and not only do I not get any lens, I haven't even gotten any tears for my troubles. Just a bunch of "you've defeated" and nothing else! I'm going loony here.
I also think the it is the Evil Eye that is in Glacier as well.
A party of 48-50 will easily be able to take these down. The drop is rare, so it may take a few kills to even get one to drop. The item is EX so you will not be able to buy or sell this item.
They do NOT stack. They are not RARE items. I am not sure about how much you can get for selling them to NPCs.
As far as the quest goes, and the wait involved, I have heard that it takes 24 hours IRL.
The lens is EX but not rare... Which means you can have more than 1 but you can't trade them. :) On the plus side, you can use them in alchemy or sell them to NPCs.
I finally got mine today....however, when I put it i the water, it tells me to wait for the lens to be puritied. An hour later, I got bored and wen't off adventuring and helped people with quests. SEVEN hours later.....
The lens is still not puritied...trie again in a while.
That rules out 1 game week of time for this quest to require.