Here you can find out where to find the values on the packaging.
Contact lens values
Contact lens prescriptions differ from eyeglass prescriptions because contact lenses sit directly on the cornea, while eyeglasses are positioned at a distance from the eye. Additional parameters are required to fit your lenses.
Strength - diopters
The strength or diopter (dpt) indicates the refractive power of a contact lens. Nearsightedness (myopia) is indicated by a minus sign (-), farsightedness (hyperopia) by a plus sign ( ).
Base curve - BC/r
The base curve (BC or r for radius) shows you the degree of curvature of a contact lens.
Choosing the correct base curve is essential for fit, as contact lenses can otherwise sit too loosely or too tightly on the eye, negatively impacting corneal nourishment and comfort.
Diameter - DIA
The DIA value indicates the diameter of a contact lens and thus determines the size of a contact lens.
The ideal diameter is chosen to ensure both corneal health and wearing comfort, and is always calculated for individually fitted contact lenses.
Zylinder - CYL
The cylinder (CYL) is a crucial parameter for correcting corneal astigmatism and is specified for toric contact lenses.
It indicates the height/strength of the curvature and is also measured in diopters.
Axis - AXIS
The axis (AXIS) is, alongside the cylinder, a key parameter for correcting astigmatism with toric contact lenses. It determines the direction in which the cylindrical effect is positioned within the lens.
Addition - ADD
The addition (ADD) is the correction value for multifocal contact lenses for near vision – specifically for age-related farsightedness (presbyopia). It indicates the additional power required for clear near vision and is always a positive value.
Zone value - D/N
The zone value of multifocal lenses indicates whether the lens is intended for the dominant (D) or non-dominant (N) eye. The design determines which refractive power is predominant in the center of the lens – "D" focuses on distance vision, while "N" focuses on near vision. This division enables balanced vision at both near and far distances.
Strength - diopters
The strength or diopter (dpt) indicates the refractive power of a contact lens. For nearsightedness, the value is indicated with a minus sign (-), and for farsightedness with a plus sign ( ).
Base curve - BC/r
The base curve (BC or r for radius) shows you the degree of curvature of a contact lens.
Accurate determination of the base curve is essential for proper fit, as contact lenses can otherwise sit too loosely or too tightly on the eye.
Diameter - DIA
The DIA value indicates the diameter of a contact lens, and thus determines the size of a contact lens.
Zylinder - CYL
The cylinder (CYL) is a crucial parameter for correcting corneal astigmatism and is specified for toric contact lenses.
It indicates the degree or severity of the curvature.
Axis - AXIS
The axis (AXIS) is, alongside the cylinder, a key parameter for correcting astigmatism with toric contact lenses. It determines the angle at which the cylindrical effect is positioned within the lens.
Addition - ADD
The addition (ADD) is a correction value for multifocal contact lenses, specifically used to treat age-related farsightedness (presbyopia). It indicates the additional power required for clear near vision and is always expressed as a positive value.
Zone value (D/N)
The zone value in CooperVision multifocal lenses indicates whether the lens is intended for the dominant (D) or non-dominant (N) eye. The design determines which refractive power is predominant in the center of the lens – "D" focuses on distance vision, while "N" focuses on near vision. This division enables balanced vision at both near and far distances.
