BASE CURVE?

[Eddie]

What is meant by a "BASE CURVE" when buying sunglasses? Some models are base curve 6 and others are base curve 8. Might this be the radius of the classes if laid on a piece of paper and a circle drawn where the lenses are part of that circle? Ed

 

[skyactiv]

Might be the lens spacing. My wife eyes are spaced further apart than the average woman and she can't buy any old sunglasses.

 

[chemman]

Base curve is the actual curvature of the lens as measured from the inside of the lens using an instrument called a lens clock. The flatter the lens, the lower the base curve number. Hence a lens base curve of 6 is "flatter" than a lens base curve of 8.

Some people who wear glasses are extremely sensitive to the base curve of a lens. Having the wrong base curve and throw off an otherwise correct and accurate lens prescription (it has happened to me a couple of times).

 

[Eddie]

Thanks chemman. These are not prescription so base curve is not so important? Ed

 

[chemman]

Maybe, maybe not. You need to try them to make sure. In my wife's case, it's extremely important.