First, you must know the size of your frame which are lens width, bridge size, and temple length. They are usually on the temple,so you can look inside an existing frame. Second, you must know your prescription which you can get it from your eye doctor when you go to have an eye exam. Finally, you must know your PD which is the distance between your pupils. You can get it from your eye doctor.
Look before you leap. Search more information online to check and compare the credibility, price and the discount. There are 10 tips for buying glasses online: 1.Large Selection 2. Return Options 3. Cost to Ship 4. Wait Time 5. Customer Service 6. Try Them On 7. Look for Quality Products 8. Are They In Stock 9. Check on the Coatings 10. Include the Lenses PD means pupil distance which is the distance between your pupils in millimeters.
Be sure to choose a reliable store.You can have a look at the customers' review for the store.If most of them are complaining,change for another store.You should have a copy of your unexpired prescription so that you can fill the information needed when buying glasses.