TS EN ISO 18369-2

TS EN ISO 18369-2 is the standard that addresses acceptable tolerance limits for the dimensional and optical deviations of contact lenses at the manufacturing stage. For rigid corneal, rigid scleral and soft lenses, controlling the principal parameters helps preserve the intended optical performance and the way the lens fits on the eye.

Why tolerances matter for contact lens performance

In contact lenses, even small dimensional differences can affect lens power, base curve, diameter, thickness and overall fitting behavior. Tolerance defines how far a product may deviate from its target value; it is a quality-control concept that manages normal manufacturing variation while keeping products consistent. The focus of this standard is the tolerance limits for the principal optical and physical parameters of contact lenses.

Which lens groups are covered

• Rigid corneal contact lenses
• Rigid scleral contact lenses
• Soft contact lenses
• Principal optical and physical parameters at the time of manufacture

In general technical terms, contact lens technology combines optical correction, lens-to-cornea fit, surface geometry and material behavior. Rigid lenses are often associated with geometric precision, while soft lenses are strongly influenced by material flexibility and hydration behavior. By aligning tolerance concepts across lens types, this standard supports quality control and product comparability.