The importance of the base for glasses?

　　The term ‘base’ can be confusing when it comes to the frames of your eyeglasses – prescription or non-prescription. However, the term relates to the curvature on the front sides of the lenses. These are measured in diopters (units of measurement for curved mirrors and/or lenses) which determine the exact curves your lenses need for optimal vision. For example, Plano lenses have no power and offer zero vision correction. Therefore, the back curvature of these lenses will be the exact opposite of the front.

　　Most eyeglass wearers become accustomed to base curves over time. Still, it takes time to get used to new glasses that have different base curves. Optical experts recommend 6-base glasses instead of 8-frame bases for better adjustment and vision clarity. However, your optometrist will determine the base settings when filling out orders for prescription glasses and/or sunglasses. This is important to keep in mind when buying prescription glasses online from an eyewear specialist.