What does ‘base’ mean in frames of eyeglasses?

Added: 04-29-2023, Views: 374

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.

How important is the base of frames in glasses?

The base of the frames is a crucial component in getting the best eyeglasses. It determines visual performance and may or may not be on par with your prescription. The same also goes for non-prescription glasses frames for men and women. Here are some things to keep in mind when understanding the base of prescription glasses online:

The base relates to the standard curvature of the frame, also known as a wraparound effect.
The higher your prescription number, the more wraparound the frame is.
On average, eyeglasses should have no more than a base of 4-6. However, the base can go as high as 8, especially for non-prescription sunglasses.
Prescription lenses also have their unique curvatures which may or may not correlate with the frames you need. Therefore, try and choose the right frames that work well with the base of your lenses.

What about the base for higher prescriptions?

Frame distortions may occur with prescriptions higher than +-3.00D (Diopter sphere) and irregular PD (Pupillary distance). Keep this in mind if you fall into this category after a thorough eye examination. You may also have astigmatism: a common vision problem that causes blurry vision. This condition stems from an irregularly shaped cornea or lens inside the eye. You will need to speak with your eye-care specialist who can determine the best lenses and frames for these conditions.

When shopping for prescription glasses online, you will need a valid and current prescription. If you do not have one, simply make an appointment for an eye examination. Your eye doctor will perform a thorough exam and write out the prescription you need for regular glasses. You may also purchase sunglasses since the prescription is already present in the lenses. Again, make sure to choose the right frames for your lenses that match your face shape. This will prevent problems from happening in the future regarding fit and comfort.