Base Curve

**ILOPEZ728** · 07-03-2006, 07:53 AM

I Got A New Prescription From My Eye Doctor And It Said That The Bc Is 3.75 But When I Go To Order My Contact Online It Tells Me That My Base Curve Should Be 8 Or Up. How Do I Know What 3.75 Converts Into Or What My Actual Base Curve Is?

**ziggy** · 07-03-2006, 08:02 AM

call your doctor and have them fax you another rx

**lab fly** · 07-03-2006, 09:18 AM

The biggest problem is that you are ordering on-line.

**RGC_man** · 07-03-2006, 12:29 PM

Originally Posted by ILOPEZ728

How Do I Know What 3.75 Converts Into Or What My Actual Base Curve Is?

Consult a qualified eye care professional.

**66Lenses** · 07-03-2006, 02:13 PM

The base curve is the front curve of any lens. The higher the base curve (8-12 base) the more curved the lenses is thus making the frame more curved.

To achieve the needed near power, the lens flattens as it moves to the periphery. Because of this, the lens must be fit at least 1.75D steeper than the flattest "k" reading or about 1.75D steeper than the best fitting GP lens base curve. Remember, this steepness represents only the central 2mm of the distance zone and does not represent the overall lens fit.

You must clarify it from your doc, to say the least.

**OPTIDONN** · 07-03-2006, 02:29 PM

Looks like the 3.75 base curve is for your eyeglasses. The 8 base looks like your contact lens base curve. On a lens for eye glasses the base curve is the front of the lens. And for your contacts its the backside. So of course you need a steeper curve for a lens to fit on your eye. Or maybe your rx was 3.75 and written in the wong place. When in doubt go back to your Eye Care Professional.