This topic comes up periodically on Forumosa, but not having needed the information until now, I’d like to ask the knowledgeable people around here for current, real-time recommendations on where in Taipei to buy eyeglass lenses that are budget-priced, thin, strong and of high quality – similar to the prices and services offered by the Zoff chain of budget-priced retail eyeglass stores in Japan (zoff.co.jp/).
Specifically, I have a new U.S. eyeglass prescription in hand and need just the lenses to fit my pre-existing sunglasses frames. I know there are eyeglasses stores on nearly every corner of commercial districts in Taipei, but I’m clueless as to which shops to approach with pricing questions and what to expect from their marketing approaches and the quality of their offerings – especially when they’re faced with a largely non-Mandarin-speaking customer such as myself (though I can speak Japanese well…but even if the shopkeeper spoke English, I still am not certain of the relative degree to which I may be getting ripped off or getting a bargain, relative to the retail environment in general).
Maybe I’m unrealistic, but I was hoping the Taiwan optical market has evolved to offer prescription eyeglasses consumer options such as Zoff does in Japan, where over a several-year period in the not-too-distant past I’ve purchased multiple pairs of sunglasses lenses at the higher refractive index of 1.74 (among the thinnest and lightest lenses), including prism and appropriate polarized tinting and antireflective/scratchproofing/UVA/UVB coating – all for 12,600 Japanese yen, or 3,791 NT at current exchange rates – and regular, non-tinted single-vision 1.74 refractive index lenses for even less – in the neighborhood of 10,000 yen, or 3,000 NT at current exchange rates.
Zoff also uses high-quality, thin and strong Japanese lenses, even at their reasonable price points, and I’ve never had a bad pair of lenses made there of the several pair of regular and sunglass lens’ prescription eyeglasses I had done in the past over a several-year period. There are budget-priced chains in Japan that aim for a lower demographic (“Hachi” is one that comes to mind) that cater to students and the like, in Ximen-type places like Shibuya, Tokyo, but Zoff, and Muji Ryohin like them, in my experience in Tokyo, aim for the slightly higher-income demographic market with more upscale retail locations and offer corresponding higher quality product, usually including frames and lenses in one reasonably priced set.
As for Costco, I haven’t checked them out yet in Taiwan, and do know they are typically relatively inexpensive; however their U.S. optical shops (and thus presumably here?) only sell prescription lenses as thin as the refractive index of 1.67 (about 25% thicker than 1.74, as was explained to me by a Costco optical shop staff member in the U.S., so I’d ruled them out when purchasing prescription lenses recently in the U.S.). My preference for the higher 1.74 refractive index is to keep the lenses as light and thin as possible, and if such high-quality, thin-lens options exist at a reasonable price in Taipei, it’d be great to know about… 
At any rate, sorry to be so long-winded but thanks in advance for any input on the matter!

