base curve

Also found in: Acronyms.

curve, base (BC) 

1. The shallower principal meridian of a toroidal surface of a toric lens. The other meridian of the toroidal surface which has the maximum power is called the cross curve.
2. In a meniscus lens, the shallower of the two surfaces.
3. Of a range of lenses of different powers, a surface power common to all the lenses in that range. See periscopic lens; back optic zone radius.
References in periodicals archive ?
Aspheric lenses do not necessarily provide better optical performance than best form lenses, but simply provide comparable performance without the restrictions imposed by best form base curve selection.
38% of the nominal, but its spread versus the base curve remained at the level of 233 b.
A 3D online calculation module can be used as an interactive demonstration tool which shows exact base curve, shape and substance at any point on the finished lens.
Because many of the corneas being fitted have a very steep central curvature, SiHy lenses with shorter base curves are preferred eg, Acuvue Advance (Johnson & Johnson) (base curve 8.
Its spread versus the base curve totally remained at last year's level and formed 249 b.
75DS, which has a front surface nearly parallel to the back surface, won't dramatically alter the shape to which the base curve of the RGP lens is being fitted.
The diameter and the base curve of the trimmed button as per measurements were made by using City Crown Semiautomatic Lathe-Cutting Machine, Japan.
However, a contact-lens prescription also includes the manufacturer, type of lens, base curve, and diameter.
Also, lens measurements such as power, diameter and base curve are included.
Base Curve Eyewear is the luxury division of REM Eyewear, a leading designer and marketer of optical and sunglass eyewear worldwide.

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