Two floors within a shopping complex of prescription glasses and sunglasses. You can go with or without a prescription. Opticians will check your eyes on site and within a day (or a week if the prescription is complex), you'll have a new pair of glasses. Why go? Because you'll pay a fraction of the price that you do at home.
Muling Road #188, 4-5 Floors (穆棱路188号4－5楼)
Taxi or Metro Line 1 - Shanghai Railway Station stop (上海火车站). The glasses market shopping mall is across the intersection from the south exit of the railway station.
I was really impressed. It's only taken me six years to get to this famed (among expats) market. There are so many stalls with so many glasses to choose from - it could be a dream come true or your worst nightmare if you have trouble with choice. I took my dad who has been wearing an ill-fitting pair of US$300 plastic frames for a couple of years. For less than half of that, he bought two pairs of new frames with bifocal lenses that actually fit. The market is great also for prescription sunglasses. You can bargain prices down a bit, especially if you are buying more than one pair of glasses.