What is the ANSI standard for cylinder power ranging from 2.00 to 4.50D?

The ANSI (American National Standards Institute) standard for cylinder power specifies how accurately the power of a lens should be measured, and for cylinder powers in the range of 2.00 to 4.50 diopters, the tolerance is set at 0.15 diopters. This means that when a cylinder lens falls within this range, any measurement must be within 0.15D of the prescribed power to meet the standard.

Understanding the significance of these tolerances is crucial in ensuring that patients receive corrective lenses that adequately meet their vision needs. Accurate measurement of cylinder power is particularly important for individuals with astigmatism, where even slight deviations can impact vision quality.

While other options present different tolerance values, they do not align with the ANSI standard applicable to this range of cylinder power. This precise understanding helps opticians comply with industry standards and provide quality eye care.