The base curve is printed on the blister and your lens prescription as BC. Here are all contact lenses with 9.0 mm, sorted by lens type – with the diameter (DIA) of each lens so you can match both values on your blister.
No lens matches this selection.
The same base curve does not mean the same fit: diameter, material stiffness and lens design also play a part, and two lenses with BC 9.0 can behave differently on the eye. Changing products is therefore a job for your optician, who checks how the new lens sits. The list shows which lenses are available in this base curve and what they cost.
The base curve (BC) describes the curvature of the back surface of the lens in millimetres: the smaller the value, the more curved the lens. It is matched to the curvature of your cornea during fitting. 9.0 mm is within the usual range for soft lenses; many products come in exactly one base curve, some in two or three.
Every blister and box shows the base curve as BC (for example “BC 9.0”), next to the diameter as DIA and the power as PWR or D. The same values are on the lens prescription from your fitting. All lenses on this page have BC 9.0; each card shows the diameter, and you can narrow the list down by it.
Both values describe the fit: the base curve gives the curvature of the back surface, the diameter the size of the lens. A flatter base curve fits looser at the same diameter, a larger diameter fits slightly tighter at the same base curve. That is why the two values are always fitted as a pair – and why this page shows the diameter of every lens.
More about the base curve of contact lenses
Diameter and base curve come from the fitting at your optician. Convert the power from your spectacle prescription with the prescription calculator.
