The 8 Best Places to Buy Contacts in 2021 Fact checked by Ashley Hall - Verywell Health

Prescription: If there's one singularly important takeaway about buying contact lenses, it's that you need a current eye prescription before shopping around. Why?

1. Contact lenses are medical devices. Wearing ill-fitting or incorrect lenses could actually damage your vision. You should get an eye exam once per year and verify or update your contact lens prescription accordingly. Credible vendors won't fill prescriptions for contact lenses that are more than one or two years old.
2. Speaking of credible vendors, per the Federal Trade Commission, it's illegal to sell any kind of contact lenses to someone without a legitimate prescription. This includes cosmetic lenses, like ones that simply change the color of your iris without correcting your vision. 
3. You may need a different type of contact lens based on your vision, like if you're near-sighted versus far-sighted or have astigmatism in one or both eyes. This is something only an eye doctor can tell you based off of an eye exam. Sometimes different eyes need different accommodations, too, so knowing your specific vision needs for both your left and right eyes is critical.

If you already wear glasses, you can't use your glasses prescription to buy contacts. Contacts correct your vision in a totally different way than glasses—including measurements for the curve and diameter of your eye—so you need a prescription specifically designed to work for contacts.

Lifestyle: Whatever your normal day-to-day optical needs are, there's probably a lens type to suit them.

"To determine which contacts are best for you, it's important to speak to your eye doctor regarding your contact lens routine," explains Vanessa Hernandez, optometrist at New York Eye and Ear Infirmary of Mount Sinai in New York City, including how often you want to dispose of them, how many hours per day and how many days per week you will wear your lenses, any allergies or problems with eye dryness, and if you plan to sleep or shower in them.

For example, people with severe seasonal or environmental allergies might want to choose daily disposable lenses; over time, longer-wear lenses may accumulate too much microscopic dust, pollen, and debris to be kept in place comfortably. On the other hand, if you work long shifts, unpredictable hours, or travel frequently, lenses that can be worn for one month at a time—through every activity including sleep—could be better for you.

Convenience: Since contacts are a bigger inconvenience than glasses in terms of maintenance, you probably want to minimize the strain on both your budget and your supply.

"Convenience is a big factor and if you prefer to purchase your supply throughout the year, online retailers can offer more flexibility and mail your supply quarterly," says Dr. Hernandez.

On the other hand, you may be more limited when committing to auto-deliveries from a particular company. 

"Subscription-based contact lens services offer convenience as well as peace of mind," says Brad Brocwell, optometrist and vice president of clinical operations for Now Optics, "[but] the disadvantage is some subscription-based sites only offer their own private label contact lenses, which may not be the best choice or modality for some customers."

Legitimacy: Look into all your available options to find a seller that will offer you the most affordable contact lenses, and do some research to make sure that seller is maintaining a high level of quality service. 

Specifically, you should verify that:

• the company only sells contacts approved by the Food and Drug Administration (FDA);
• the company requires a current prescription from customers;
• the company is not plagued with poor online reviews and/or complaints to consumer regulation boards;
• and the company does not make unauthorized changes to your prescription or attempt to sell you a similar but cheaper or lesser-known brand than the one your doctor prescribed.

"Companies who offer to change the prescription without a visit to the eye doctor will often use a subpar contact lens that uses outdated technology and materials," explains Dr. Hernandez, "which increases the risk for complications and infections in contact lenses."

Safety: Most people can safely wear contacts without damaging their vision, but there are rare cases when contacts aren't compatible with your eyes. This includes medical conditions that causes excessive dryness or inflammation, certain kinds of allergies or infections, or if you work around a lot of environmental debris. 

Also keep in mind that correct maintenance of your contacts is hugely important; your contacts are only safe to wear if they're being cleaned, stored, and disposed of properly. Failure to maintain your contacts can easily lead to eye infections that could, if left untreated, damage your vision temporarily or even permanently.