In one form or another, eyeglasses have existed for centuries. Ancient Roman scholars and medieval monks used blown glass to magnify manuscripts. Paintings from the 17th and 18th centuries depict well-to-do folks sporting eyeglasses—including Benjamin Franklin, who invented bifocals. Contact lenses only came into common use in the mid-20th century, but all-time smarty-pants Leonardo da Vinci had conceptualized them as early as 1508.

Luckily, glasses and contacts have come a long way. The 75 percent of American adults who need some sort of corrective eyewear can choose between comfortable contacts and thousands of fashionable frames. Still, shopping for new specs and contacts can be a major hassle.

Our surveys of local consumers reveal sizeable differences in customer satisfaction. Some outlets were rated “superior” for “overall quality” by at least 90 percent of their surveyed customers, while others earned such favorable ratings from fewer than 50 percent.

Price also matters. Our undercover shoppers found identical eyeglass frames and lenses cost more than twice as much at some outlets than at others. For eyeglasses, the least expensive sellers were usually online. But shopping for glasses online can be challenging, since it’s hard to tell in advance which frames will flatter your face.

Unfortunately, for eyeglasses, because they don’t sell the same products, it’s difficult to compare prices among some of the largest chains for the exact same frames. Comparing costs is further complicated by the dominance of EssilorLuxottica, which not only manufactures millions of pairs of glasses annually but also markets and sells them via thousands of retail stores it runs, including For Eyes, LensCrafters, Pearle Vision, Sunglass Hut, and optical departments at Target. It’s often difficult to assess whether designer frames the company makes are worth hundreds of dollars more than a nearly identical, far-less-expensive model that possibly was made in the same facility, probably for less than $5.

For the limited selection of specs they carry, we found Costco, Walmart, and Warby Parker offer low prices, and Costco and Warby Parker also get fairly high overall ratings from their surveyed customers.

For contacts, we found the lowest prices online, but some internet sellers were more expensive than the lowest-priced local brick-and-mortars. If you’re replenishing a year’s supply and not changing brands or type, there’s little reason not to grab the savings by buying from a low-cost supplier.