Constantly changing fashions means a constantly changing selection at eyewear outlets. There have been design evolutions: Today’s glasses are lighter and available in more styles than ever. New contact lenses are more comfortable, and disposables require no maintenance.

Despite these innovations, shopping for specs and contacts can be a major hassle. The survey of thousands of local consumers by the nonprofit Delaware Valley Consumers’ Checkbook found that many vision centers get very low scores for the advice their staff offers, promptness and other issues. And our undercover shopping research indicates that many stores have prices that are way too high.

Dozens of stores received “superior” ratings for overall service quality by at least 80% of surveyed customers, while others got such favorable ratings from fewer than 50%. In general, chains and franchise operations were rated lower than independent firms, but there was variation among each outlet type. Until Feb. 5, Inquirer readers have free access to Checkbook’s ratings of local optical shops for quality and price at Checkbook.org/Inquirer/Eyewear.

» READ MORE: How to wear a mask and not fog up your glasses

When shopping for new eyeglasses, you can easily feel overwhelmed by the endless racks of styles and brands. But much of this variety is an illusion: The lion’s share of eyeglasses on the market — including those sold under popular designer brand names — come from just a few Italian companies with names you probably won’t recognize: Luxottica, Marcolin, Safilo.

Luxottica not only manufactures millions of pairs of glasses annually; it also markets and sells them in more than 7,000 retail stores it runs. Though the name “Luxottica” doesn’t show up on their signs, when you head into LensCrafters, Pearle Vision, Target’s optical department, Sunglass Hut and many more outlets, you’re shopping in a space or store the behemoth company owns or controls.

Luxottica owns several brands outright, including Ray-Ban and Persol. And other name-brand specs are created by the eyewear giants through licensing agreements, meaning that those Coach, DKNY, or Michael Kors frames might all have been churned out in the same factory. With only a few companies controlling both the manufacture and the distribution of most of the frames sold, it’s tricky to figure out whether you’re getting a good deal or not.

The way to assess value is to buy from a store that offers great advice — where you’ll be told whether more expensive frames warrant their higher prices or that you’d do just as well with a lesser-known brand. Many independent retailers stock a wide variety of frames. Some companies don’t sell any Luxottica products. For example, Warby Parker offers $95 single-lens glasses in funky, fashionable frames. It began as an internet-only business that would send frames for customers to try on before ordering.

It still offers the try-on options for online orders, but the company has opened more than 130 brick-and-mortar stores in the United States and Canada, including several in the Philadelphia region.

Checkbook’s undercover shoppers collected prices for 18 models of eyeglasses (with single-correction lenses) and found that some Delaware Valley outlets charge twice as much as others. For example, for a pair of Ray-Ban RB5228 frames, prices at surveyed stores ranged from $198 to $508. The best news: You don’t have to pay more to get great advice and service: Checkbook’s shoppers often found low prices at the highest-rated stores.

Checkbook researchers also collected prices for six brands and models of contact lenses and found even larger store-to-store differences in prices and fees. For example, for a one-year supply of Biotrue ONEday daily disposable contact lenses (plus exam and fitting), prices ranged from $564 to $962. Among vision centers, Checkbook found that Costco, along with a few independents, offered the lowest prices for contacts.

You can save a lot by buying from some — but not all — online-only retailers. Checkbook shopped for glasses and contacts at a sample of internet stores. For eyeglasses, prices at almost all the online retailers were substantially lower than at surveyed stores — several sites offered prices that were less than half of those offered by local stores. Online sellers not only tend to offer very low prices, but they also carry a much wider selection of frames.

An obvious disadvantage of buying eyeglasses online is that, unless you’re replacing frames you like with an identical model, you usually can’t try on various frames to see how they’ll look on your face. Some sites let you upload a picture of yourself so you can try on frames virtually or will send frames for you to try on, but most shoppers will find it’s far easier to compare options in person. Fortunately, liberal return policies are the norm among online sellers of eyeglasses, so you can return the specs easily if you’re not completely satisfied.

As with eyeglasses, Checkbook found that online contact lens retailers were less expensive than local outfits — charging about 30% less than local brick-and-mortar retailers. But you can’t count on low prices from all online suppliers: Some well-known online sellers offered prices higher than the average found at the lowest-priced area outlets.

Delaware Valley Consumers’ Checkbook magazine and Checkbook.org is a nonprofit with a mission to help consumers get the best service and lowest prices. It is supported by consumers and takes no money from the service providers it evaluates.