Studies show that a single base curve of 8.4mm managed a “good or better” fit in approximately 90% of individuals,1 and base curves of 8.4mm and 8.6mm together encompassed 98% of individuals.2017-09-01

Should I get 8.4 or 8.8 base curve?

The 8.4mm base curve is still the likely best fit for the majority of eyes. In instances when the 8.4mm lens is too steep, the 8.8mm lens allows a flatter option. This is more likely needed in smaller eyes, and possibly in some very flat corneas.2008-07-01

How do I know if my base curve is too big?

If you realize that you've gotten contact lenses with an incorrect base curve, you may feel it. Lenses with the wrong base curve feel like they won't settle right on your eyes. If the lens is too curved for example, it may just slide around in your eye. Every time you blink, it may shift its position.2016-09-02

How do you find the base curve?

- For plus power use the spherical equivalent (SE) and add 4.00 diopters to that. For example, if you have an Rx of + 2.00 sphere, the base curve for the lens will be approximately 6.00.
- Rx +2.00Sph -> [+2.00 +4.00D] = 6.00BC.

Does base curve have to be exact?

The base curve number would be a number between 8.0 and 10.0 millimeters and would be more precise because these lenses need to fit just right. Now that most contact lenses dispensed are soft lenses, this measurement doesn't need to be quite as precise.2016-09-02

What base curve do I need?

The most basic rule is that you always want the base curve to be as close to +6.00 as you can get and still have the Rx work. ... The more minus the power (less plus power to minus power) the lower plus the base curve will become. A high minus Rx may even have a base curve of +0.25 or even 0.00.