Contact lenses by base curve
The base curve is printed on every blister as BC. Pick the value of your lens to see all contact lenses available in that base curve – sorted by lens type, with prices from many online shops.
- 8.3 mm 30 products · 1 Daily lenses, 6 Monthly lenses, 4 2-week lenses, 19 other · from £ 19.90
- 8.4 mm 55 products · 12 Daily lenses, 16 Monthly lenses, 5 2-week lenses, 22 other · from £ 10.90
- 8.5 mm 41 products · 14 Daily lenses, 9 Monthly lenses, 2 2-week lenses, 16 other · from £ 18.59
- 8.6 mm 156 products · 42 Daily lenses, 81 Monthly lenses, 7 2-week lenses, 26 other · from £ 11.90
- 8.7 mm 79 products · 17 Daily lenses, 41 Monthly lenses, 3 2-week lenses, 18 other · from £ 14.29
- 8.8 mm 44 products · 9 Daily lenses, 20 Monthly lenses, 15 other · from £ 14.49
- 8.9 mm 28 products · 11 Monthly lenses, 17 other · from £ 14.90
- 9.0 mm 22 products · 5 Daily lenses, 1 Monthly lenses, 16 other · from £ 18.59
What the base curve means
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. Soft lenses usually range from 8.3 to 9.0 mm; many products come in exactly one base curve, some in two or three variants for flatter or steeper corneas.
Where to find the value
On the blister and on the box you will find the base curve as BC, next to the diameter as DIA and the power as PWR or D. The same details are on the lens prescription from your fitting.
Base curve and diameter belong together
Both values describe the fit: the base curve sets the curvature, the diameter the size of the lens. A flatter base curve sits looser at the same diameter, a larger diameter sits tighter at the same base curve. That is why the fitter chooses the values as a pair, and why the value pages show the diameter of every lens.
When a change belongs to your optician
The same base curve does not mean the same fit: material stiffness and lens design differ from product to product. If you want to switch, have the fit of the new lens checked – contact lenses are medical devices.