answered about 18 months ago by nakji
I got mine at the optician at the top (bottom?) of Giang Vo - just near the Horison hotel. I'm afraid I can't remember the name or address, but it's quite a big shop. Contacts cost 80,000 dong each - 160,000 dong for a pair. They did a vision test in the back of the shop to get my prescription, which was free.