Which statement correctly describes the power steps for soft contact lenses?

Which statement correctly describes the power steps for soft contact lenses?

• A. Common powers use 0.25D steps; higher powers use 0.50D steps for powers > 6.00D
• B. Common powers use 0.50D steps; higher powers use 0.25D steps for powers > 6.00D
• C. Both always use 1.00D steps
• D. Steps vary randomly by manufacturer

Answer: (B)

Power steps describe how finely soft contact lens powers are incremented. In practice, the typical range of common powers is in 0.50 diopter steps, which is a convenient balance between having enough options for most prescriptions and keeping manufacturing and stocking manageable. When prescriptions get higher than about ±6.00 diopters, manufacturers often switch to 0.25 diopter steps to allow even more precise corrections. Small changes in power can have a bigger impact on vision at higher prescriptions, so finer steps help dial in the exact correction a patient needs. So the statement matches how lenses are usually offered: 0.50D steps for most powers, with 0.25D steps used for higher powers to provide finer adjustments. It isn’t standard to use 0.25D steps across all powers, nor to rely on 1.00D steps, and while some brands may have variations, the described pattern is the common industry practice.

Power steps describe how finely soft contact lens powers are incremented. In practice, the typical range of common powers is in 0.50 diopter steps, which is a convenient balance between having enough options for most prescriptions and keeping manufacturing and stocking manageable. When prescriptions get higher than about ±6.00 diopters, manufacturers often switch to 0.25 diopter steps to allow even more precise corrections. Small changes in power can have a bigger impact on vision at higher prescriptions, so finer steps help dial in the exact correction a patient needs.

So the statement matches how lenses are usually offered: 0.50D steps for most powers, with 0.25D steps used for higher powers to provide finer adjustments. It isn’t standard to use 0.25D steps across all powers, nor to rely on 1.00D steps, and while some brands may have variations, the described pattern is the common industry practice.