If you’re shopping for a new pair of eyeglasses, you may get sticker shock when you pick up a pair of frames at your local optician. It certainly doesn’t help that vision insurance doesn’t always cover glasses — and when it does, it may not cover the whole cost. Another option is to take your shopping to the internet, where you’ll find a better selection and lower prices.
Here are six things to know when buying glasses online.
Your Prescription Status
You’ll need a current prescription to order glasses online. How recent your prescription has to be varies, but most people can expect their prescription to be valid for a year or two. Check to see if yours has an expiration date. If it doesn’t, contact your eye doctor to ask. If your current prescription has expired, you’ll need to schedule an eye exam first.
The Right Frame Size
The great thing about shopping for glasses at a local store is you can try them on to see how they fit. Fortunately, some online stores will mail you frames, so you can test them out at home to find the perfect fit, just like you would in the store.
If you’ve found the perfect frames at an online retailer that doesn’t offer this service, there’s a solution: take a pair of glasses that fit and shop for frames in the same size.
These are the three measurements used for frame sizing:
- Lens width: Exactly what it sounds like.
- Bridge width: The size of the piece that fits over your nose.
- Temple arm length: The length of the arms that extend back toward your ears.
Assuming you have a pair of glasses that fit, you’ll find these measurements written inside the frame from left to right (lens width, bridge width, and temple arm length). They will typically be on the inside of one of the temple arms, but may be on the back of the nose bridge.
The hardest part of getting these numbers is being able to see the small print when your glasses are off; if you can’t make out the measurements, snap a picture with your phone and then work from that. You can find more details in this easy-to-understand infographic.
Your Pupillary Distance
Pupillary distance is the distance, in millimetres, between the centres of the pupils of both eyes. It’s a crucial measurement because your lenses need to be centered on your pupils. If they aren’t, the glasses will likely cause eyestrain and make it hard for you to focus.
Your pupillary distance may be written on your prescription. If not, you can typically call whomever prescribed your glasses and ask, or simply go to your local optician’s office and see if you can get a measurement there. There may be a fee for measuring, but it isn’t likely to break the bank. You can also find plenty of online tutorials on doing this yourself, or your favourite online retailer may offer its own method for finding your PD. Warby Parker, for example, lets you submit a photo that its staff will examine to determine your proper PD.
Picking a Lens and Coating
Whether you buy online or offline, someone will probably try to upsell you on lenses and coatings. Anything beyond a basic, single-strength lens will add to the cost, but some upsells can be worth it. Here are the lens types you’re most likely to hear about:
Polycarbonate and Trivex Lenses
These lightweight plastic lenses offer great durability. They’re an ideal choice for kids or for general wear when playing sports or doing other outdoor activities.
High-Index Plastic Lenses
As the name implies, these lenses have a higher index of refraction. In plain English, that means they’re the thinnest lenses you can get — and they can stay thin while providing clear vision for people who need stronger prescriptions. The higher the refractive index of these lenses, the thinner they are.
Made for people who wear bifocals (glasses that have two strengths for seeing near and far) or trifocals (which have three strengths), progressive lenses don’t have lines where one strength lens meets the next. This is definitely a cosmetic improvement, but can also make it easier to see because there isn’t a line in the middle of your lens.
These lenses change colour in the sun, making your standard glasses work as sunglasses, too — though they won’t necessarily get as dark as sunglasses. The biggest brand in photochromic lenses is Transitions.
For lens coatings, some — if not all — of the coatings we’re about to list may be included with your lenses. However, that doesn’t mean you won’t be offered better (and more expensive) versions of these coatings. Are higher-quality coatings worth it? Maybe… and maybe not. Find out exactly what you’re getting so you know if it’s worth it to you:
- Anti-reflective coating makes your eyes more visible, but can also help you see by reducing glare. The latter can be especially good if you work with computers frequently.
- Scratch-resistant coating is just what you think it is. No glasses are fully scratchproof, but having some scratch resistance is good, especially if you’re hard on your glasses.
- Ultraviolet protection is important, because your eyes can be damaged by exposure to UV light as much as your skin can. Many lenses are capable of blocking 100% of UV light without any additional coating, though.
- Anti-fog coating can keep your glasses from fogging up when you come in from the cold.
What to Do About Adjustments
Even the perfect pair of glasses could require some adjustment to fit just right, but ordering online doesn’t mean you’re out of luck. You can make adjustments on your own if you have some idea of what you’re doing, and most eyewear retailers — like Zenni Optical — offer instructions on how to get your lenses just right.
If you aren’t keen on the DIY option, most opticians will adjust glasses — even if you didn’t buy from them — for a small fee. Some online retailers partner with local stores to provide in-person adjustments, and others may refund you the cost of an adjustment. Check before you buy!
Is the Retailer Trustworthy?
A web search for “buy glasses online” brings up dozens of stores, but which one’s right for you? Look at the retailer’s online reviews. When you decide to make a purchase, check that you’re entering your credit card information on a secure page (look for a little lock icon in your browser).
Also check the store’s return policy and warranty. Some retailers won’t allow you to return prescription lenses, while others offer generous return windows. When ordering online without the opportunity to try your glasses on in person, it’s important to have a good return policy to be sure you get a pair of glasses that’s right for you. A solid warranty is also a good sign that the company stands behind its products — certainly something you want for a product as important as your glasses.
Elizabeth Harper is a professional writer and a non-professional technology enthusiast, with a keen interest in how tech is changing the world we live in. This post originally appeared on DealNews.